For our NATO Style Straps , just select the width 1mm wider than your watch lug. For example, a 22mm NATO will squeeze into a 21mm lug without any issues.
Fitting a Quick Release Strap requires a little more ingenuity. Once again, select the strap that is 1mm wider than your watch lug (i.e. 22mm strap for a 21mm lug). Then, remove the original quick release spring bars and replace them with the appropriate, odd-width spring bars.
If you're unsure how to remove and replace quick release spring bars, it only takes a few seconds and there's a video to show you how to do it here. Odd-width quick release spring bars can be purchased here.