Finning techniques
Often it is advisable to not kick in a flutter kick near the bottom or a reef. By using different finning techniques in combination with good trim (see perfect trim demonstrated by Andrew Gorgitsis here) and buoyancy control, you will quickly gain a new-found elegance and better form underwater.
Frog Kick
Allows for a better trim, and less disturbance of the ground.
Keep your legs at a 90 degree angle, and perform a frog kick similar to your breast stroke. Get someone to show it to you, as it is quite easily learned by observing and trying. Same goes for all the finning techniques mentioned here.
See Clare Gledhill, GUE Instructor, perform a good demonstration of a Frog Kick: http://www.youtube.com/watch?v=H2O7ro67HZs
Helicopter Turn
Purpose: To turn around or change direction without forward movement - useful in wrecks and caves, but also when navigating over reefs.
See Chris, perform a good demonstration of a Helicopter Turn: http://www.youtube.com/watch?v=KPk_VHI6J2E