I usually don't bother doing this because I find it easier to train up the Mage/Alchemist spell knock knock in Arnika later in the game. A lock and trap skill of about 15 should get you through everything until then, especially if you have some knock knock picks to make things even eaiser. Beyond that I find that my rogues progress well enough naturally. Nonetheless, there are some good training tips at Flamestryke's site if you haven't seen them already:
http://www.flamestryke.com/wizardry8...ow8/tt-lt.html
I'm sure Scatter will have something more to add!
Good luck!