It does depend a lot on the field and the airplane. Too much up elevator can cause the problems mentioned above, but on many fields and with some planes, if you don't use some, you can't taxi or get going fast enough to lift off.

The trick is in using enough elevator to get moving, then ease off the elevator to avoid lifting off early. In full-scale, it's a "soft field takeoff", and it works with models as well.

Also, once the plane is moving, but well before you can take off, the rudder has quite a bit of effect, so if the nose wheel is up off the ground, you still have plenty of control over the plane. In most cases, you shouldn't need to get the nosewheel that high up, and it can lead to lifting off too soon, but it can be a helpful technique.

I do agree that larger wheels help.

Also, be sure to check how the plane is sitting. On grass, with a flat-bottom wing, you want the bottom of the wing level with the ground. That actually gives the wing a slight positive AOA sitting on the wheels, which will help you lift off. If you are nose down, the plane will have a tendancy to dig in, then pop off the ground early. If the plane is nose-high, it can lift off early on it's own, and will have a tendancy to "wheelbarrow" when the mains lift, but the nosewheel is still touching, which can cause a wild and random turn in either direction. Nose-up also leads to bounces on landings.