I am no expert in soldering tiny parts with lots of pins, but I have soldered a few components with 0.4 and 0.5mm pitches, some as high as 100 pins, onto Schmartboards.
I know the Schmartboard is specifically designed to help you solder these things easily, but I only ever get the “non-EZ” versions of their boards, and use solder paste with them. Typically I’ll place the component on, get it nice and square, tape it on, square it up again, and then solder one or two pins on either side of the device to hold it in. From there, I just apply a tiny bit of solder paste to the pins (often dispensed from the head of a pin!), and solder a few pins at a time.
I did have one pretty bad bridge once, when I applied too much paste. The solder actually worked its way behind the metal part of the pin, between the pin and the flatpack. It took a couple tries, but by applying a small gob of paste, solder-sucking it up, and using an exacto-knife to clean out the rest, things went okay. It also was a lesson to avoid trying to solder 20+ pins in one go with a ton of solder paste… 
I hope that helps a little bit. I know that if you have a rework station you can sometimes just heat the chip up and lift it right off, but I’m just using a good soldering iron with a fairly fine tip.
best of luck,
silic0re