One tip is to learn the shortcuts to frequently used things (just got my Vista a few weeks ago and love it). Pressing the zoom in / out buttons on the satellite screen changes contrast. This is good since the satellite screen is the first one to come up, and you will want to change the contrast for the lighting you are currently in.
On the compass screen (called Navigate IIRC), pressing and holding the page button will toggle the electonic compass on and off. It's nice to leave off while you are able to move at a good clip (thereby saving batteries), and turning it on when getting closer to the cache, so it will point towards the cache even while you stop and check out the surroundings.
And very important, something I just figured out today when I was sure there must be a way to do it: press and hold the joystick switch to mark your current location. Until today (about 3 weeks or so), I've been going to the main menu, then selecting mark. This is a lot easier.
thanks fo all the good tips!