If you're making your own (or purchasing, for that matter), having or being able to make a front edge that is slightly rounded makes a big difference. Depending on your posture and ergonomic use of the desk, a sharp, right angle front edge can be annoying. It doesn't have to be much; an 1/8 inch or 3 mm quarter round makes a big difference.
As for adjustable height in a (partially) self-built desk, I've used these IKEA trestles:
VIKA ARTUR
http://www.ikea.com/us/en/catalog/products/00144763
I was fortunate to get some off-white ones, that apparently didn't sell too well but look great in my place, for some ridiculously low sale price. Normal price seems a bit high for a "budget desk".
P.S. IKEA U.S., your now-even-heavier Flash site blows (chunks) this morning.