Find the exact balance and cruise slowly.

	1° Moving at a slow pace on a very easy gear, just kick-in your best pedal to lift the front wheel while seated.
	2° Keeping the knees very loose, carry on pedaling slowly. If you tend to accelerate, lean backward and use the brakes slightly.
	3° You should find a point of balance where you just keep the bike rolling without accelerating. Adjust your balance with the hips.
Other Tips
Really start a low speed. Lean backward while seated, and use the brakes if you tend to fall backward to reajust the balance. Then pedal again to keep the same level of speed. Eventually, you'll be able to roll slowly, slow down and carry on again. It really takes some practice but its worth the feel.

The 'Manual' is a variant of the wheeling where you just carry on rolling without pedaling, down a slope for example. It is really smooth and classy. See the animation.
Down the edge of a wall (Kenny)