Thanks for the trees, I'll start working with them with my next map

As for cliffs... hell, I don't even know where to begin with. Get some mountains, erase the high ones, add emboss to the low ones, "flat" them (transform tool)? Maybe it'll work...

As for the rivers and lakes! I must have missed that fact with rivers flowing closely to lakes, so thanks for pointing that out, but I really can't agree that a lake has to have a river entering and leaving it. I know a few lakes that are "stand-alone". It's hard for me to explain stuff when english is not your first language.

Sometime today I'll try to post some of my next, larger project