Get out a lot. This is esential and seems to be a really good way to train without having to pay or go indoors with lots of pale sad people. There are plenty of places to go in all weathers and the commited boulderer will manage to climb outside all year round. The only bad times are when it gets too hot and midgey. Get out when it's cold.
Friction is the key element to most problems on the grit.
Everything feels much easier when the temperature is around freezing. I can't do it. Get some good excuses. Get some decent rubber. Rubber shouldn't make that much difference however I am certain 5.10 is the best of the lot.