What are some ways to make your writing look longer than it actually is?

I’m going to guess you are thinking about the word count. This is one of the bigger problems with first time writers. Brevity is way better as long as the story is told and each strand is neatly tidied up. If you have a story that is perhaps 20,000 words long but you want 30,000 instead, just stop and think before adding in unwarranted sentences and words that don’t gel too well. If the story is told then that’s the correct word count.