I thought most ball bearing types had a torque setting but I may be wrong.
The best way is to spin the wheel while tightening up the nut until it binds and the wheel stops. Tighten it up a little more to make sure the bearing is seated all the way. Back it off then spin the wheel while tightening again. Youll want it to just start binding then back it off one or two notches until the cotter pin can be inserted for the fronts, or for the rears back it off a notch or two until you can bend the lock washer over. Then tighten the outer nut as tight as you can.
This has been covered a bunch before, so you may find clearer instructions doing a search.
Remember, we'd love to see some pictures!
Jeff