Having done the 60 degree triangles and diamonds last time we probably ought to look at 45 degree diamonds – these are the ones used in 8-pointed and Lone Stars.
As for the 60 degree diamonds – first cut a strip the width of the diamond plus 1/2 inch for seam allowance. Then trim the ends of the strip to 45 degrees using the 45 degree line on the ruler. Keep the strip folded in two as you will need half your diamonds cut left to right and half right to left – keeping the strip folded cuts these two at the same time without you having to worry about it. If using two colours for your diamonds. open the strips out and place them right (or wrong) sides together and then cut.