One kind of sculptor adds lumps of clay and then pushes, pulls, and smooths them. Less experienced writers are additive, looking for more words or pages to fill an assignment. They don’t want to write anything they won’t use. They think before they write.
Another kind of sculptor chips at a block of stone, taking away what doesn’t belong. More experienced writers are subtractive, always looking for what to delete and compress. They throw away lots of perfectly good sentences. They write in order to learn what they think.
As you grow as a writer, you will progress from additive to subtractive, from looking for more words to write to looking for more words to delete.
In many organizations, people speak of “crafting” a document or “putting together” a document rather than “writing” it. These terms emphasize the cutting and shaping and de-emphasize the composition.
The key factor is that block of stone. It’s your research. If you are looking to something to fill pages, then you haven’t done enough research. If you do enough research, that is, if you collect enough information, data, experts’ statements, and illustrations, then you’ll have more than enough to write, and you’ll be on your way to looking for things to delete.
Don’t think of research as a couple of facts and quotes you pin onto your essay like ornaments on a Christmas tree. Think of the research as the block of marble that gets chipped and drilled into shape. Your sources aren’t some nuisance to prove you did your homework. Your sources make up most of your essay. Your contribution is to organize them (put them in order; topic sentences; transitions) and to make inferences from them, to explain what they mean.
Your research is what gives substance and weight to your claims (thesis statement and topic sentences). You aren’t going to be paid for what you have to say. You’re going to be paid for selecting and shaping what others have said and written and then for making inferences, for explaining it to your audience according to their needs.