Fly Girl just got a dry suit. I suspect force of habit had her writing wet suit, but I am sure she si asking about dry suit techniques.
Masterof0's description is spot on. Pull the neck seal away a bit and roll yourself up as small as possible. If th suit fits correctly it will leave very little air in the suit and you should feel almost vaccuum packed when you stand back up.
As for jumping off a boat, there are times in current when you want to jump in and go straight to the line leading to the anchor line. I have found that doing the above to vent the suit, combined with the normally negative buouyancy that comes from a full tank, or set of doubles is enough to ensure you are negatively buoyant.
A caution here is to be 100% sure your tank valves are on and your reg is functioning as if you go in with them off and are negative, you will sink and the increasing squeeze can make it even harder for you to reach the valves to turn them back on. I had a well meaning but more or less moronic mate turn off both my posts just prior to my jumping off a boat in current last year. I got suspicious with his proximity to my valves and double checked them before jumping off. I discovered I no longer had gas. Life could have gotten interesting had I not double checked.
The moral being if you go in negative, be very, very careful to ensure things are correctly set and working before you jump. There is no real need to jump in negative, unless you are on a boat in strong current, and dumping a bit of reamaining gas on a non current dive is not a big issue. All other things being equal, there is nothing wrong being positive on the surface if something does go wrong on entry.
