You'll probably get about as many different answers to this as you would if you'd asked how to run in an engine [img]i/expressions/face-icon-small-smile.gif[/img]

The first thing you should do before you even look at the balance is to lightly sand all edges of the prop including the tips to get rid of any mould flash. I hand start so I take particular care to round off the trailing edge more than usual where my finger will go. Then do an initial check for balance. If one blade is heavier then first sand off any paint such as brand names or tip paint. If it's still heavy then sand carefully and evenly all over the upper curved surface. There's no need to worry about altering the airfoil shape because you'll only be sanding off maybe a few thousandths of an inch and the props just aren't that accurately made, most of them have terrible airfoils anyway [img]i/expressions/face-icon-small-smile.gif[/img]

Chances are when you're finished the prop will always stop with the blades level and always the same orientation. This means that the prop hole isn't perfectly centred but for other than competition (extreme rev) engines this isn't a problem.