Hi- I've already gotten so much out of this forum, but am getting to specifics so I thought I'd join up and post- thanks in advance! So i'm starting in on bonsai cautiously, and have bought three woody, small-leaved herbs that I thought might be suitable on which to practice I'm just looking for a few general tips on how to start training these. I'm wondering:

a) What's the best way to get thick trunks and a good bonsai shape... let them get big and then prune way back to make bonsai?.... gradually shape them and let them grow into bonsai starting now?... maybe the trunk will thicken as the plant ages either way?

b) When I am going to start training these plants, do I do the normal root pruning and stick it in a small pot?

c) Do they want a bonsai soil, or just potting soil?

d) Is there a good season for pruning these, or is it more or less ok to whack away at any time? Right now it's november in Canada, and they're indoors in a cool room under a grow light with a humidity tray.

Just for reference, the plants are: a Lowry's Peach Autumn Sage, a Prince Rupert Geranium, and a Powis Castle Wormwood. They are young plants, all around half or 3/4 of a foot tall, and around .5 to a centimetre thick. Thanks for your time!