Also, coming from a senior–you truly can recycle essays. Maybe not the Why X school? essay, but you can write an outline that you use for most schools. The supplement I wrote for my RD school was fantastic and happened to fit most of the prompts for many of my schools. Yes, you do end up writing a lot of supplements, but one of my friends who goes to Yale now and also applied to 20 schools said applying to 20 schools was one of the best investments they made. I understand where people are coming from in advising a short list, but with the increasing competitiveness of college apps, applying to 20 schools (if the apps are good) could increase your chances of getting better aid/a school that you like more. I honestly think people are so judgemental when it comes to lists/CC in general, talk to your college counselor, your parents, seniors at your school, and make the choice for yourself.