The things for which you give XP, and to what degree(s), have a big influence on the play style you see at the table, in my opinion."Monster XP" systems lead to more combat and combat oriented characters, "story XP" systems lead to more goal oriented play and metagaming, and "gold XP" systems lead to full on ransacking. " personally like "Exploration XP" where the majority of XP comes from finding new and interesting things -- which might be a monster, or a plot point, or a treasure chest or anything else. By granting XP for uncovering new areas, wilderness or dungeon or even urban, I get to clearly communicate to my players that I want them to explore the world before them without "promising" to give them monsters to fight, a story to follow or treasure to be had as their reward. Those things are there, but the real reward is the exploration itself.