Practice.

Play some "real-time" video games. Especially good, are flying combat sims, or R/C flying programs.

Any flight sim that lets you operate the plane from the perspective of standing on the ground can be helpful. MicroSoft's Flight Simulator is good. (I used FS98, which is cheap now...) ther's a downloadable R/C sim called FMS.... lots of others to look at.

If you have a 1980's style joystick (similar to a single TX stick) its almost as good as using one of the simulated R/C transmitter boxes such as you get with "Real Flight G2" or R/C Pilot Pro." I picked up one of the old style joysticks at a garage sale for $1 a couple of years ago.

Your initial flying practice mainly needs elevator and aileron control. Its easy to add rudder and throttle training when you get to the airfiled with your model. Do some taxi practice... figure 8's on the runway... or in the parking lot, and you'll get used to throttle and rudder. A yardstick taped to the top of the wing, along the main spar and sticking up will prevent take-off in case you get going too fast.