While the plain style is the preferred style in most settings today, facility with style comes from diversity of options. You can't choose the best way to say something if you can't think of many different ways to say it. That is why learning to write means practicing using a dictionary and the thesaurus, to make sure you choose the best word from all of the possibly relevant ones. But the equivalent of a thesaurus does not exist for whole sentences. You have to make your own. The Renaissance scholar Erasmus made one for his students, which he called De Copia Or on Words and Ideas. A piece of that text is reproduced below. Before that, however, I've reproduced some introductory remarks by Ephraim Emerton.
Desiderius Erasmus of Rotterdam By Ephraim Emerton
The word copia is a difficult one to translate. Its first meaning of " abundance " is liable, as Erasmus begins by showing, to be understood as mere verbosity.
" We see not a few mortals, who, striving to emulate this divine virtue with more zeal than success, fall into a feeble and disjointed loquacity, obscuring the subject and burdening the wretched ears of their hearers with a vacant mass of words and sentences crowded together beyond all possibility of enjoyment. And writers who have tried to lay down the principles of this art have gained no other result than to display their own poverty while expounding abundance."
He proposes to give only certain directions, and to illustrate them by formulas which may prove- convenient to writers. Copia includes the ideas of richness and variety, but must avoid the errors of mere quantity and change. Not all fulness contributes to completeness of effect, and not all variation in style helps towards real illustration of the thought. Here, as elsewhere, we find Erasmus the true apostle of common-sense. After all, the purpose of rhetoric is primarily to say something worth saying, and to say it in such a way that it will commend itself to the reader. The purpose of these directions will therefore be to show how the essential point may be condensed into few words and yet nothing be left out, and how, on the other hand, one may expand into copia and yet have nothing in superfluity.
The first rule of the Copia verborum is
" that speech should be fitting \apta\, good Latin, elegant and pure \_purd\. . . . What clothing is to the body, style is to the thought; for just as the beauty and dignity of the body are heightened or diminished by dress and care, so is thought by words. They are therefore greatly mistaken who think it makes no difference in what words a given thought is expressed if only it can be understood. So also there is the same principle in changing the dress and in varying the speech. It is our first care that our dress be neither mean, nor unsuited to our figure, nor of a wrong pattern. It would be a pity if a figure good in itself were to be spoiled by mean garments; it would be ridiculous if a man were to appear in public in woman's dress, and a disgrace if one were to be seen in a preposterous garb or with his clothes turned back side before. " And so, if anyone tries to put on an affectation of copia before he has attained the purity of the Latin tongue, he is, in my judgment, no less ridiculous than a poor beggar, who, having not a single garment fit to wear, should thereupon change one set of rags for another and come out into the market-place to show off his beggary for wealth. And the oftener he should do this, would he not seem so much the more foolish ? I think he would. And just as foolish are those who affect copia and yet cannot say in plain words what they want to say. As if they were ashamed to appear to stammer a little, they make their stammering only the more offensive in every possible way, as if they were on a wager with themselves to talk as barbarously as ever they can. I like to see a wealthy house furnished in great variety, but I want it all to be elegant and not to be filled up with articles of willow and fig-wood and vessels of Samian crockery. At a splendid banquet I like to have many kinds of food brought on, but who could bear it if anyone should serve a hundred sorts of food not one of which was fit to eat ? "
Having thus admirably laid down the rule of moderation and good taste, Erasmus goes on to details. He shows what kinds of words are to be avoided and to what extent. His comments on the use of obscene words are interesting in view of the general practice of his time and, indeed, upon occasion, of his own practice. Certain words are obscene because they represent obscene things; others because they are twisted from their harmless meanings. " What then is the principle of obscenity ? -- nothing more nor less than the usage, not of anybody and everybody, but of those whose speech is correct." Of himself it must be said that in general he lived pretty well up to his principles. Where he offends in this respect it is generally in a kind of composition, as, for example, in many of the Colloquies, in which he simply lets himself go, producing his effect by a freedom which he carefully avoids in other forms of writing. He was, if one may say so, artistically obscene.
Below is an exurpt from Desiderius Erasmus, Copia: Foundations of the Abundant Style: De duplici copia verborum ac rerum Commentarii duo, trans. and ed. Betty I. Knott, in Collected Works of Erasmus: Literary and Educational Writings 2, ed. Craig R. Thompson, vol. 28 (Toronto: University of Toronto Press, 1978), 302.
Your letter mightily pleased me.
To a wonderful degree did your letter please me.
Me exceedingly did your letter please.
By your letter was I mightily pleased.
I was exceeding pleased by your letter.
Your epistle exhilarated me intensely.
I was intensely exhilarated by your epistle.
Your brief note refreshed my spirits in no small measure.
I was in no small measure refreshed in spirit by your grace's hand.
From your affectionate letter I received unbelievable pleasure.
Your affectionate letter brought me unbelievable pleasure.
Your pages engendered in me an unfamiliar delight.
I conceived a wonderful delight from your pages.
Your lines conveyed to me the greatest joy.
The greatest joy was brought to me by your lines.
We derived great delight form your excellency's letter.
From my dear Faustus' letter I derived much delight.
In these Faustine letters I found a wonderful kind of delectation.
At your words a delight of no ordinary kind came over me.
I was singularly delighted by your epistle.
To be sure your letter delighted my spirits!
Your brief missive flooded me with inexpressible Joy.
As a result of your letter, I was suffused by an unfamiliar gladness.
Your communication poured vials of joy on my head.
Your epistle afforded me no small delight.
The perusal of your letter charmed my mind with singular delight.
Your epistle was delightful to a degree.
Your letter affected me with extraordinary gladness.
As a result of your letter I was affected with singular gladness.
Your epistle was the great joy to me.
Your missive was to me a very great delight.
Your epistle was an incredible joy to me.
How exceedingly agreeable did we find your epistle!
You could scarce credit with relief I find your missive.
Your epistle was to us one of great delightfulness.
Your letter was very sweet to me.
Your letter was the source of singular gladness.
Your letter mad em positively jump for joy.
Your letter having arrived, I was transported with joy.
When your letter was delivered, I was filled with delight.
On receipt of your letter, an incredible delight seized my spirits.
Once I had read your affectionate letter, I was carried away with a strange happiness.
Your epistle poured the balm of happiness over me.
Your writing to me was the most delightful thing possible.
The fact that you had written to me was extremely pleasurable to me.
Your honoring me with a letter was the most agreeable of occurrences.
Your brief note mad me burst with joy.
How overjoyed I was by your letter!
I was both please and delighted that you communicated with me by letter.
When your letter arrived, you could have seen me jumping ro all the joy I felt.
That you paid your respect by letter was assuredly a satisfaction to me.
Nothing more wished for than your letter could have been growth me.
Your letter has reached us, and eagerly looked of rit was.
Nothing more desire than your letter could have ben brought us .
Not unpleasing was your epistle tome.
Your by no means displeasing letter has arrived.
your missive by no means failed of a welcome.
Your epistle was to me the sweetest of the sweet.
I read and reread your letter with great pleasure.
It was not without the greatest pleasure that I received your letter.
The man who delivered your letter conveyed a wealth of joy.
Wonderful to relate how your letter entranced me.
The pages I received from you sent a new light of joy stealing over my heart.
Your letter promptly expelled all sorrow from my mind.
I sensed a wonderful happiness in my spirits when your letter was handed me.
From your letter an unaccustomed happiness swept over my spirits.
Your letter cause me to rejoice to the full.
Because of your letter my whole self exulted with joy.
It is difficult to say how much happiness was occasioned in my by your letter.
I can hardly find word to express the extent of the joy to which your letter gave rise.
It is wonderful to tell what a ray of delight beamed forth from your letter.
Good God, what a mighty joy proceeded form your epistle!
Heavens, what causes for joy did id your letter provide!
Ye gods, what a power of joy did your missive supply!
The happiness occasioned by your communication is great than I can describe.
Your messenger brought me a deal of pleasure.
You could scarce credit he load of happiness your letter conveyed to my mind.
I cannot find word to tell the joys that your letter loaded on me.
Your letter heaped joy upon me.
I rejoiced greatly at your letter.
I found singular pleasure in your letter.
Your missive showered a wealth of gladness upon me.
At the sight of your letter the frown fled from my mind's brow.
If you aren't yet full, Erasmus wrote another book on style, Ciceronianus: A Dialogue on the Best Style of Speaking