I agree with Minnflyer, but I do lateral balance on all of my planes. I just do it as a matter of habit when I balance the plane. A good way to do it is get some good strong fishing line, tie it around the prop shaft of your motor and tie the other end around fuselage at the tail and leave yourself some slack so you can pick it up. Then lift the plane and see what happens. If a wing drops down then it is heavy on that wing and some weight needs to be added to the opposite wing. If you have already covered the plane then you will need to use the technique that Minnflyer lists in his [link=http://www.rcuniverse.com/magazine/article_display.cfm?article_id=84]"Balancing How-to"[/link]. If you haven't covered yet you can epoxy the weight directly to the frame. I prefer to completely assemble and balance my plane before I cover it. I think it's easier to add weight this way so you don't have to cut away covering to add weight. Of course I do a final balance check once the plane is covered.

Hope this helps

Ken