They like to see interest, but they don't want to feel pestered. I sent a letter, an email, or made a phone call (one type of communication only) every month or two at the schools I applied to. I don't know if it helped or hurt, but I'm a happy MS1 now 🙂
Another tactic is to try and get in touch with the Dean/Director/Assistant Dean--whoever is in charge of admissions basically. If a representative is coming to your school or community, go hear them speak, get their contact information, and contact them--ask if they're free for a phone call or meeting, so you can ask questions about their program, which is one of your top choice schools. If the people in admissions say they don't do that kind of thing, then they don't do that kind of thing. Best of luck!