I've had players complain about having an odd amount of XP. These odd amounts were given as special bonuses to player actions. I found that a key item is that if you are going to give out 1-4 XP for something cool then be sure to do it often enough so that the player doesnt have an XP count of 151 or 203.

I gave more EXP for the first few sessions of our campaign (25-40) and less later (10-20) except for special moments. This was so the PCs got a boost in the beginning so they could get to their character concept quicker. I also ask the Players to try and split their EXP 50/50 or so between Combat and Non-Combat advancements. I don't pull out the calculator or anything and it's not always even but my group knows I'm not a fan of min-maxing and I throw in enough non-combat skill checks that they know it's worth spreading their EXP around.