I was told or I read somewhere, that your borders should be divisible evenly by the size of your blocks. Like a 10" block would use a border like 2", 5", 1". A 12" block would use a border like 6," 4", 3" 2", 1", or a combination of those. Or.....you could use any size you like. <grin>
I love stripes in borders or binding. I think a small 1" or 2" border in a stripe is very effective.