Rich has the answer to long rim life, tight even tension.
P.B. I have found through experiance that a 4 cross wheel will ride softer than a 3 cross, but the 3 cross is more durable and will tend to bend less on rough roads when properly built and tensioned. I build my favorite wheels for me and for many other happy cycling using the Mavic 519/520, DT- 14/15 DB spokes and shimano ultegra hubs using the cross 3 lacing, I also find that for banging around I run the contiental ultra 2000 700-28C and for long distance I like the top touring.