As a 1500 hour instructor I must confess that I avoid using the radio if possible as well. OK, most of the time at work it's not possible but if I'm going on a long cross-country jaunt and don't need an ATC service then I generally plan to avoid controlled airspace and just keep quiet. A bit of common sense, like don't fly near other airfields or through somebody's instrument approach and you don't need to say much, and who's to say what frequency other aircraft you may see are on anyway?
All that said, it's a good idea to be able to speak to ATC when you have to, and unless you're at Heathrow or somewhere where you really do need to be hot on the R/T, remember that if you can't recall the standard phraseology then use plain English instead - they'll know what you mean.