Angie has recommended tights from Express. They have two diamond-ish styles. I have one:
http://www.express.com/full-ti.....savf=Color
They are nice tights, but the pattern is a little more subtle than I figured. Perfect if your outfit has some pattern or busyness. I'm still on the lookout for bolder ones - for when the outfit is plain. . .
Oh, yes - they are pricy, so with any of their hosiery, I do the buy-one-get-one-half-off then use a printable coupon (there is one right now) for $15 off $30. It makes them about $7-8 per pair.