Look for Z's drifting from the tall grass. Enter that particular patch of grass for a chance to get a surprise attack on a sleeping Micromon. Trainer fights can result in lots of experience, but can be difficult. Other Micromon trainers are marked with an icon of crossed swords above their heads. Trainers will not fight with you unless you give them permission; make sure your Micromon are strong enough to win before engaging them. When your Micromons win a battle, the experience rewarded is divided between the ones that participated. When trying to level a specific Micromon, use a smaller party size to give it a higher portion of the total experience.