Look at where your dump valve sits when you have the suit on. That spot will need to be the highest point, for you to vent gas from the suit. Think about how you need to position your body and your arm to do that.
Anticipate -- dry suits vent slower than BCs, so you cannot get behind or you are headed for the surface. When I use both my suit and BC for buoyancy and squeeze, I like to vent the BC first on the way up, so that the suit expands to where it is very easy to vent when the BC is empty. Getting the very last bits of gas out of a dry suit can be challenging, which is why it's important not to underweight yourself. I'd rather see someone 2 pounds heavy than 1 pound light.
Pay attention to your feet. One of the difficult things to recover from in a dry suit is getting feet up and buoyant. You will be taught a couple of procedures for managing this, but in practice, it's very difficult to execute them before you are hopelessly behind on venting. When you start to feel your feet going up, correct it NOW, even if it means getting feet down for a bit. This will get much easier with time, but at the beginning, you need to overcorrect.
Hope those are helpful. A dry suit definitely adds a layer of complexity to buoyancy control, but they sure are nice for warmth!