Here's some tricks for Darkstone that I discovered and haven't seen mentioned anywhere. The first 2 can only be done in single player games, the 3rd can be done in both single and multi.

1. Surrogate Pool Drinker - If you switch to solo mode and leave the character you're not using at a mana or health pool, whenever you get low just switch to the character by the pool, walk a short distance from the pool, then click on the pool and before the character gets there to take a drink switch back to the other character and that one will get their health or mana filled instead of the one by the pool.

2. Permanent Magic Door - If you want to keep your magic doors from crumbling when you go back through them, when returning through the door from town use the character who did NOT create the magic door to enter the portal. If you are in a multi player game, 2 characters can both make a magic door then return from town using the other guy's door instead of your own. This way you can keep them open and use them over and over.

3. Earn More Money - Of course you want to use a character with the Trade skill to do all the buying, selling, and repairing (if you have one). But if you have the character with Trade skill pay the blacksmith to repair all your items before you sell them you will actually get MORE money. He gives you a discount on the repair and pays your more for the fully repaired item than what he would have paid before + the price he charged you to repair it.