All the posters are correct in using the rudder in coordination with airlerons. Under these conditions you have the option of either sidesliping or crabbing when encountering crosswind conditions. Switiching to a more logical and less professional approach, add a crosswind runway or runways to your existing field layout. Face facts people, must RC pilots just want to bore holes in the sky.
I flew at at a site in South Carolina that had three runways and when the wind changed so did the pit area. No one complained they all enjoyed themselves.