There are as many ways to do this as...But after a lot of reading, watching other people fly, and making a number of costly mistakes, I think this is generally the best way:
If you have little or no experience, use the straight arm/stiff wrist method until you're comfortable taking off, flying around, putting the plane at the altitude you want, not panicking anymore, etc.
Most good stunt flyers hold their hand vertical, with the elbow bent as much as 90 degrees, and the hand centered in front of the chest. Always follow the plane with your hand through the maneuvers.
A high priority is to get comfortable with inverted flight if you haven't already.
RW, the rule book says 5 feet for level flight and all bottoms. Here's a link to a good description of the modern pattern:
http://www.clstunt.com/pattern.htm
I'm having a lot of fun dealing with the challenge of the pattern. Pretty good at the rounds, the squares are next on the agenda. This is not an easy thing to do really well.
One more thing while I'm thinking about it. Go to this link and print out this article by Art Adamisin. Art is one of the grand old men of Stunt, judge, teacher and flyer. Great advice. Awesome thing is that it is free.
http://www.netax.sk/hexoft/stunt/tips.htm
Then if CLPA turns you on, go to the PAMPA web site and order "The Stunt Book" by Dave Cook, for all the gory details. Even if you never compete, practicing the pattern will sure make you a better flyer.
Kelvin