Much of my writing is formal, in that it follows a standard musical form. The rondo form in particular carries a certain elegance in that the recurring A sections are memorable and are separated by new contrasting material (sections B, C, etc.). I find that if I make the A section just long enough to be memorable, the audience will anticipate its return with a sense of familiarity. Then the other contrasting sections can be longer, as they are heard only once.
Here is an example rondo form I have used recently, for the third movement of the string trio that I composed for my graduation term project. The superstructure is A B A C A Coda. The A section is in binary form:
||: a :||: b :||
Then sections B and C each feature two themes the come one after another, and then they are repeated once more with slight variation:
a b a b′
where for b′, I replace the second half of its statement with some material that is derived from both the a and b of this section. I then finished off with a coda derived from material of section B, but with much sparser notation of sustained notes, leaving the audience hungry for more. (I hope!)