Solder tenth inch pins with ease - hpaluch/hpaluch.github.io GitHub Wiki
I needed to solder two 2x20 pins to Lattice ispMACH 4256ZE Breakout Board without short-circuiting all pins together :-)
Here is how I did it - just small paper template taped to board:
NOTE: do not worry about burning the edges of hole in paper - just cut another one. It's cheap and renewable.
And here is the result: