I received this comment from Reese Laundry on my post about not dividing the XP:
Like Daren, I do this in my BX/OSE games for monster XP only, but not treasure. IT's a minor boost and not unbalancing, I don't feel. I've considered the idea of exploration or mission XP, but haven't tried it yet. I'd be interested in seeing a post at some point on how you do it and how it's worked out for your table!
Since I've got a bit of spare time today, might as well address it.
When I started my West Marches game, one of the things I did was go back and read a post from Jeff Rients about exploration XP, and decided to work that into the game.
Each hex that gets explored has a basic XP value. Any monster lair has a value for its discovery, as well. These values increase the farther the party gets from town. I've got bands 4 hexes deep (or about 1 day's travel) that set the value of these.
Special locations, or performing certain actions at special locations, or encountering an iconic creature in a certain region, are all worth bonus XP.
Originally, I set the game up for 5E because that's what all the players wanted to play. So the XP values were pretty small, especially in the initial band. When I switched to Classic D&D, I didn't shift the values right away, so they ended up being inconsequential. After a while, I upped them.
One thing that I need to improve about my game, actually, is telegraphing where the special areas are that can earn bonus XP. For quite a while now, the group has been setting their own goals. And I've not found the right balance of throwing out rumors and keeping things mysterious. I'm working on it.
I think I need to make a Google Docs with the rumors and just post the XP amounts on it if the rumor is successfully investigated.
Anyway, here are the current values I'm using for exploration of a hex and discovery of a lair. The special area XP is pretty variable, but usually two to five times that of a lair discovery award, depending on how easy/hard or influential I think that special is.
First Band (1 to 4 hexes from Silverwood): Hex 100xp, Lair 200xp
Second Band (5 to 8 hexes): Hex 200xp, Lair 500xp
Third Band (6 to 12 hexes): Hex 500xp, Lair 1000xp
Fourth Band (13 to 16 hexes): Hex 1000xp, Lair 2500xp
Fifth Band (17 to 20 hexes): Hex 2500xp, Lair 5000xp
Sixth Band (21 to 23 hexes): Hex 5000xp, Lair 10,000xp