Back when I was learning the bow stall, I figured out a little trick that involved filling my boat full of water and using the side of the pool to balance off of. As a result, I learned how to balance on my bow very quickly. I've since shared the technique with some other paddlers and they seemed to really like it, so I thought I'd share it with all of you as well. I hope it helps. By the way, this will teach you how to balance once you are vertical. So make sure you learn the double pump.
The process is as follows:
1. Fill you boat full of water. The more water you use, the more stable you will be.
2. Using the side of a pool, prop yourself up into the bow stall position.
3. Once vertical, find the sweet spot, where you can balance your boat by using very little arm strength.
4. While still vertical, grab your paddle (it should be right in front of you) and slip into the pool.
5. Maintain your balance using your paddle.
6. Using a cup, empty out some of the water from your boat.
7 Repeat steps 2-6 several times, emptying out more water each time.
Once your boat is empty, you will have the proper balance to hold a bow stall.
Now just get good at the double pump, and you're in business.
Here is a video of how to do it.
www.kayak559.com/Kayak559/Resource.html
(Video #5)
Good Luck.