I just used ordinary plastic hinges with a little metal rod in them. I completely cut off all the control surfaces (ailerons, elevator and rudder)...then made sure the edges were smooth. To fit the hinges I just cut little slots in the EPP to allow for them to snugly fit in. CA glue was used to hold them in place.
Although I have a second aileron servo, this was just installed for better aileron control as I only have a 4ch transmiter thus can't use a flaperon feature...Though I don't really feel this plane needs flaperons, but I guess I have a lot of space where I fly.
There is so much travel now I have put hinges on...so much I had to tone it down with the ATV on the transmitter. She doesn't fly so well with huge amounts of travel, after all she's not a 3D weapon! but I definately recommend installing proper hinges as it offers a very cheap and worthwhile upgrade.