Preflight the airplane.
Make sure the battery is charged and the gas tank is full.
Make sure your gas tank is full, too.
A tired pilot is a sloppy pilot.
Look to see who's already flying, where are they flying, and what are they doing.
Where is the wind coming from? How steady is it? The goal is to takeoff into the wind from a nice, long, smooth, and level runway.
Use 15 degrees of flaps, just don't forget to take it off after you finish climbing.
Ideally you want to stand behind the model.
If not possible, do your best.
Also, try hard to avoid having the model fly behind an obstruction after it takes off.
Whether it is your best buddy or a pole, you don't need that kind of excitement.
Most clubs require the use of a spotter.
Use one even if you don't think you need one.
Make sure they know what their job is.
Too often they think their job is to keep the idle conversation going.
It is not.
Their job is to alert others about what your airplane is about to do, and to alert you about what the other airplanes are about to do.
If your spotter starts getting chatty, give him a job to do to keep him busy.
Ground Roll Make sure the runway is clear.
Nobody else about to take off or land.
Announce your take off in a loud voice.
Apply power smoothly and steadily.
Don't stop moving the throttle up until you hit 100% power.
Keep a close eye on the direction the airplane is headed.
If it starts to veer off, smoothly apply a rudder correction.
If it is a taildragger, chances are that it will first lift up the tail wheel and then take off all of its own.
Tricycle gear airplanes are designed to require up elevator to take off.
So when do you know it's the right time to pull back on the stick? With experience, you will know when is the right time to give up elevator.
Otherwise, give it some up and see what happens.
If it doesn't take off, neutralize the elevator and wait for the speed to pick up some more.
Then try again, being gentle with the stick and watching the model carefully for signs it is ready to take off.
It takes a little bit of practice, but before long you will know instinctively what to do.
In The Air Immediately after take off, watch out for the p-factor and be ready to apply right rudder to compensate.
Give the airplane a chance to pick up speed before getting into a steep climb.
This is key! Too many times folks give full up elevator right after taking off, when the airplane has barely enough airspeed to stay up.
The result is then a nasty stall/spin accident.