THE BASICS OF FLIGHT: BODY POSITION
I've already covered Speed/Height ratios. You can't go too fast low to the ground or too slow high in the air without destabilizing the dream.
How you position your body is also important. Everyone assumes you have to stretch your body out horizontally to fly, like Superman, but that's actually bad form.
Dreams are built from things we already know. The only time we experience movement stretched out flat in the waking world is generally when we go swimming. By assuming the superman flying position, which is also the swimming position, you run the risk of evoking swimming physics. This is why swimming physics are so common in dreams of flying. You end up trying to paddle the air.
When are we at our best movement wise? When we are STANDING. We have the best control over movement when we are standing. If you fly from a standing position, you have access to those movement protocol in the same way you have access to swimming ones while stretched out horizontally. I find standing gives me the best flight control, to stop, hover, accelerate, anything.
Another useful position is seated like you are driving a car. BUT... this one is only useful if you've spent a few years behind the wheel. This creates a style of movement strongly tied to a specific body position. The accelerations we experience while driving cars is very useful in a lucid flying scenario, and makes flying very easy.
The theory here is the same a dressing up for a phone interview. Lock down a specific inference point with useful baggage.