Since we're posting cheese:
Play with xp sharing to all. After you beat the bandits at Oleg's, don't just buy a handful of mercs -- stay at xp level 1 and buy 30, 50 or more. Buy every possible build you would want to use at any point in the game. Buy multiples of your favorite ones and many of the low level ones (example: human mad dog barbarian, 20 str, weapon focus bardiche, precise strike. Example: human mad dog barbarian, 20 str, 18 dex, point blank shot, precise shot ). Buy 4-5 advisor mercs to cover all stats, in case you lose some real advisors during the game.
When you run out of money, strip all your mercs and sell your junk items items. When you run out of money again, do a quick trip to a couple easy locations to gather treasure.
Once you have your full roster of mercs, you are ready to play for real. Now, each time you go out on a run, you can put together whatever party works best for the upcoming areas, while your other 50 characters sit back at base leveling up for free. If a character dies, you don't need to waste 6k gold on a raise dead -- dump the corpse and swap in his clone. When you return to base, you don't always need to spend 8 hours resting -- swap in five non-fatigued characters who have fresh spells. When you are finally forced to rest at Oleg's, your entire roster will heal and regain spells, not just the active party.