I just received a good tip on balancing wings. You can find them in the last few posts of this thread.

http://rclibrary.com/viewtopic.php?p=413#413

I just balanced my wings. Took two small pieces of lead split shot (fishing weights) and glued them into the main spar at the tip of my Spirit wings. Used goop to attach them.

As per the post link above. I joined the two wing halves and taped them together temporarily. Then I ran a string along the joint and balanced the wing inverted on the string. It became pretty obvious which wing was heavy. I added the shot to the light wing.

I guess you can laterally balance the fuselage, but on my glider, the main balance issue is the wings as they are over 6 feet wide. The fuse has very little impact compared to the wings. On something smaller, this might not be the case.

Hope htis helps.