Tunebooks are great - every session should have one. A collection of "our favourite tunes" can take a bit of organising - the session probably needs to have a sub-group that's willing to take this on - but if you use ABC (or Noteworthy) it's very easy to maintain & distribute.

I've been going to the Beech session since it started, and I've got to say that if I hadn't had the chance to practise the tunes in between times I'd still be a struggling beginner (instead of a struggling improver). I recently decided to attack the tunes that were still putting up resistance more systematically; I've split the Beech tunebook into "easy" and "hard", and I play a few of the "hard" tunes every day. (I'll probably find I've gone rusty on the "easy" tunes now.) It's easy to do this kind of thing with ABC.