I would recommend that you guys start with the balance point method because it is easiest to maneuver your safety razor and gives you the best grip out of all of them. (primandprep.com)
This method I typically don't use just because I'm so comfortable with using the balance point method. (primandprep.com)
The professionals have a five point method for teaching babies to crawl, called the 5P Baby Crawling System. (pregnancy-info.net)