What others have said above re vests. Would also recommend experimenting with different nappy brands if you experience frequent leaks at any point. I found that different brands can fit different babies better. For example, my eldest son and my youngest son were both long skinny babies in comparison to their other brother who was quite chunky (nothing to do with their weight btw, just their individual build). I did more clothes changes with them until I changed brand, they did better in Huggies than in Pampers. My girls were over 10lbs and seemed to be best with Pampers.
Changing nappies doesn't always work, but its worth bearing in mind if you do use disposables. Grab as many free samples as you can get your hands on x