Balancing is done where where the kit manufacturer states, if they make such a statement, otherwise at the fuselage.

I once had a kit that dictated that it be balanced part-way out from the root and at a certain distance aft of the leading edge. This was on a 12' wing glider, and that balance point was used because if you balance at the fuselage, the long wings with their large amount of dihedral put a lot of weight above the model, so it would tend to rotate on over. If you balanced at the wingtips, there was enough flex in the wings that the model would always seem to balance.