I really don't worry too much about solder bridges before the part is soldered.

Most of the time, I'll use a syringe to place the paste, then in the process of heating the board, the paste thins and spreads out. It then often runs into other pads. However, once it 'turns' and becomes solder, it wicks up as it should and, if you have the right amount of paste, all the bridges go away. I haven't done this on a board without a solder mask though.

As for temperature settings... I've had the best luck not using a nozzle, with a fairly low air flow setting. If anything, you don't want it to be too hot. Start with a 'cool' setting, keep it several inches away, and see what happens. As the paste warms up, it will become much more liquid and probably spread out a bit. That means it's getting close to reflowing. I usually move a bit closer with the nozzle now until it does reflow.

Like most things, it's not hard to do once you've had some practice doing it. And yes, too much air will move the part(s), which can be very annoying.

Some more SMT tutorials
http://www.sparkfun.com/commerce/...=tutorials

ahh, videos; a bit different method, but would still work fine
http://www.sparkfun.com/commerce/...MD-HowTo-8

For BGA, QFN, or other parts with pads on the bottom, I prefer to heat from the bottom of the board, rather than the top. Seems less likely to damage the IC that way.

-Dave