For the type of border you provided an example for, I made mine (works with any version of PS that i know of) by setting up an inner and outer border with a space between, then overlaying a grid on another layer, and using the select too to cut the grid out so it only showed between the borders. flatten those, then paintbucket alternating sections. I found you end up with more predictable control on the size for this sort of grid (plus i find it's easier if you want to do something like red/black alternating) instead of calculating out the size of the brush and spacing percentages, but I hate math

(toff is right though, it's worth really getting to know the basics until they are second nature to you, it will serve you well in the longrun)