ORIGINAL: cwrr5

For one servo per aileron (or any control surface) :
Basically, make a small hatch that's just large enough for the servo on it's side. Cut an opening for the servo arm, and use two uprights made from hardwood (NOT balsa) , the same width as the servo. Screw the servo to the uprights, and install the hatch with screws into a frame in the bottom of the wing. Sizing depends on your plane and servo, may have to adjust the opening for the servo arm to get full travel.

You can use this method in any size plane, I have a small electric that uses the same mounting for the aileron servos, except I used plastic sheet for the hatch and micro servos. same difference.

If you want to use one servo for both ailerons, try sullivan flexible pushrods. Route the outer housing through holes in the ribs, make a gentle bend out towards each control horn and support the tube along it's length with scrap. Run the inner pushrod through and attach at each end.