Sketching is something that often gives me trouble and is the root cause of a lot of my more "stream-of-consciousness" works. When I first begin a work, I'm constantly striking out whole sections and/or inserting whole other sections into gaps in the existing framework - sometimes this is by hand, but more often in a Finale file that can be easily expanded, spliced, etc. Once a piece begins to "take root," as it were, and develop into more than the rough beginnings of a sketch, however, things become increasingly one-to-one with the eventual product. Many of my works have unfolded for me much as they would for a listener, which makes intellectual guidance of a piece difficult, at best.
I've been trying to work on my sketching somewhat, lately, partly as a result of this thread and partly out of a desire to get back to writing
new things, rather than polishing, arranging, and orchestration previous works. Usually, I work in a 3-stave format, or occasionally 4-5 for more complex areas: a treble, bass, and octave-transposing bass staff are usually my most common trio. By nailing a workable range for the breadth of the string section, it gives me room to write (most of the time). I've also been sketching more and more away from the computer, which has had some interesting effects.
My ear-training is not as strong as I'd like, sadly, so if I'm
also composing away from the piano, what is written can be difficult to match to what was heard at the time; I'm getting a little better, but it's a work-in-progress, as always. The one thing I really like about sketching away from the computer is that it makes me more conscious of
what I'm writing and makes it harder for me to fall into the trap of repeating things needlessly because the copy button is no longer readily available and tempting.

-Matthew