When I want to try a new switch, I usually buy 10 samples first to avoid being stuck with switches I may not like. There is a serious problem with this: how a switch feels individually may feel differently in use. This is the trick I came up with to get close to in-use experience with as few sample switches as possible.
When you have only 10 sample switches, use them on these keys:
When you have 20 sample switches, you can cover more alpha keys like this:
The reason behind this trick should be obvious: usage frequency.
I found that number and modifiers keys matter less than alpha keys when testing how a switch feels and sounds in use because they are either not used as often as alpha keys or near the edges where feel and sound is much more subject to case and plate.
This trick should also work when you’re trying different lubes in-use.
Caveat: Spring weight and switch type must be similar for all switches.
UPDATE: Edited topic since this hack is useful for lubes and springs as well.