John Buckner's method is the way to do it for a good retro or initial fit. If the TE gets loose, as outlined by abacro, then the system of the TE and aileron will flutter because the mass balancing is set up for the aileron only. The 'system' of the TE and aileron will flutter in this case. Your wing may not be torsionally rigid enough, too. The whole wing and aileron may be going thru oscillations. Make sure the cabanes and struts are secure. If you cut into your wing and make repairs go ahead and make the LE of the ailerons thicker than the TE of the wing where ailerons hinge. This helps if you get flow separation on wing ahead of the aileron. Keep the TE of ailerons squared off. There are many methods to make this work. I like to make Frise type ailerons and include static mass balancing in the fwd part of the aileron. It helps reduce adverse yaw, decreases drag of weights hanging in the breeze and reduces chance of flutter. I am also 'guilty' of making mass balances on the outer end of ailerons as seen on many fullscale counterparts with the cutouts in the wings to let them pass. They look cool, too! Good luck and remember to pull power in nose down attitudes- just kidding- you can do whatever you want, right?