So I'm not sure if there is a good place for this: @ChrisGammell can move it if it needs to be.
Anyway, I was going through Open Tech Lab's videos after watching his series on the Ice40 FPGA (initially on EEVblog's channel) and he pointed out a really cool feature on the Pocket Chip PCB. It can be found at the link below.
Essentially though, for 0.1" pin headers, you can offset every other hole to get a press fit without soldering. I think this is really cool when you can use plated through holes.
I recently came across something similar in the Tron Club, but they used press fit headers with normal header holes. I haven't looked them up, but I'm sure they are more expensive than normal and less people are likely to have them on hand.
To round this out into something useful for everyone, what cool tips and tricks do you guys use in your PCB designs?