Miscellaneous Experience

A short thought expanding on some ideas I've already mentioned:

Start with xp for treasure as a given. Add the assumption that levels are fame indicators and experience mostly represents confidence mixed with reputation among the locals (which is why bringing treasure back increases your level.)

People often debate how to reward experience for actions other than combat and treasure. One way I've suggested is including xp for creatures saved, using the same system as for creatures slain. Another way would be to rate actions in terms of monetary value. If you clear a trail and set up guardposts for a new trade route, you've essentially brought additional wealth to the town; figure out how much wealth, and that's your treasure value. Adjust it for the relative difficulty (your level / HD of main enemy or damage dice of main threat.)