I like digging tunnels under the enemy's cornfields. ^_^
During one game I played on Hies, I had made this elaborate network of tunnels spanning two cornfields with deadends, hidey holes, and so forth. I would pop up, get a few kills, they would come trying to dig me up and find me and I would just pop back down and hide then crawl to the other end of the field why they're looking for me on the other end, pop up and shoot em again.