The best tip I can give is to grill corn this way:
1) Shuck the corn
2) Cook the meat until it's about 10 minutes from being done.
3) Put the corn on the grill and let it cook until some of the kernels are ligthly browned, turning it for uniform cooking and color.
4) Just before taking the corn off the grill, brush it with melted butter and sprinkle it with salt.
Yum!