Step 1: Know the Basics
In order to ride your bike no handed, you need to know the basics. First, before you start practicing, you need to make sure you are seated on the bike comfortablely and balanced. This is good to do so you have the best experience possible doing this. You don't want to be leaning to the left while you're riding because you sat more on the right of your seat. Also, you need to bike at a fast enough speed so the bike doesn't tip over. When you do not hold on to the handlebars, you have less support, so you need to go faster so the bike travels straight and does not travel shaky. In addition, you need to keep practicing. This will be taken gradually, and some people might move through the process faster than others.
Step 2: The Process
There are different hand positions that you will be doing when going through this process:
1.) Grip the handles regular, but don't use your palms and ride.
2.) Once you have mastered 1, put your fingers on top of the handles and ride.
3.) Once you have mastered 2, but aren't ready to go no handed yet, ride with your index and middle finger touching the edge of the handles. Some people might be able to skip this step, but if you want to skip it, be sure you are ready.
4.) If you have either mastered 3, or decided to skip 3, you are ready for no hands
Step 3: Things to Know
Before riding with no hands you need to know some things. If you you want to go a little slower when first riding, I have found out that the minimum constant speed you can ride with no hands is about 10.23 miles per hour on a one gear 20 inch bike. That's one pedal per second on a 20 inch bike. I don't know the conversions to bigger wheeled bikes but I know you can go slower on bikes with bigger wheels. Anyway, that is if you want to go slow. If you want to go faster, gradually increase your speed so you don't lose control. You will eventually get used to no hands riding and it will be second nature. Enjoy!