Decide who you want early then drop the other LIs on the way. Easiest way to drop J&M is when you find out they are lesbians/bi, that way you can remain friends and still be able to flirt with them. Sage, just don't let her sit behind and cuddle the MC, unless you are on the Quinn path, then keep her going until you get the choice of Sage or Others. With Bella and Jill, if you aren't too friendly with Bella then Jill probably won't like you and it's easy to keep Bella away, another way to get out of the Jill route is to say that you don't think the MC and her are suited after the Tennis Date.