tips for breathing and swimming comfortably with a snorkel?

Hi, I'm trying to figure out how to use a snorkel comfortably, preferably without a nose clip (because the noseclips keep falling off me). I use a Finis snorkel and either get water up my nose or have small bits of water accumulate in the snorkel. It's a little better when I exhale through my nose, but either way, water accumulates in places that make it uncomfortable to swim more than a 25. Even when I don't suck in little bits of water, it's really hard to get enough air, and I can feel myself panicking. After each lengths, I stop and empty little bits of water from my snorkel, and catch my breath. (I am an experienced competitive swimmer in good health, so I'm very comfortable in the water without a snorkel.) Even with a noseclip, it's uncomfortable. My son is just beginning winter swim team, and they will be using snorkels too. The coach advised for them not to use a noseclip, that they will get used to swimming without it. So I'm looking for advice for both myself and for my son, so we can use the snorkels comfortably. Any advice on breathing easier with snorkels would be much appreciated!