This is an excerpt from Mastering Skateboarding.
The nose manual is a staple trick for all experienced street skaters. In the nose manual, as you might expect, you do a wheelie on the front wheels instead of the back. It helps a lot to have your ordinary manuals down so that you understand the kind of body motion it takes to roll along on two wheels. The nose manual isn't much different once you get the hang of it.
The biggest challenge with nose manuals is that the weight of the board is behind your center of gravity. This makes it more difficult to use the board to “push” through little bumps and imperfections in your balance. As with ordinary manuals, the board sort of acts like a ballast or counterweight for your balance. When it's behind you, it becomes more difficult to make small, quick adjustments.
1. Start by rolling slowly on a smooth surface. Your lead foot should be squarely on the nose, and your rear foot should be near the tail or rear trucks bolts.
2. Keep your knees slightly bent, raise your elbows up and away from your sides, and press down on the nose so that the tail rises up. Try to bring the tail high enough so you feel your center of gravity over the front wheels. At first you will certainly go too far, and the board will dip all the way over. That's okay; it's how you learn where that perfect balance is.
3. When you feel as if you can bring the board up just to the tipping point, try to hold that position for longer and longer distances. Use your arms and hips to maintain your balance and pull the nose manual out to greater distances.
If you are getting frustrated by continuing to tip forward and fall off, try experimenting with frontside 180 kickturns off the nose. (Pivot off your nose while bringing the back end around in the direction your toes are pointing.) Try to do these slower and longer so that the 180 turns are more like long arcs. You'll find that you are doing a nose manual while you turn.
Read more from Mastering Skateboarding by Per Welinder, Pete Whitley.