I wash mine on delicate with cold water, so it's not too rough on the jeans... and I try not to wash them too often. The holes getting bigger is inevitable though, will happen with every pair. I try not to put them in the dryer because that causes shrinkage (well, I put them in there once to purposely shrink them a little). Also, to preserve the wash, I turn them inside out before putting them in the washing machine.
Hope this helps,
Ben
(Oh, you can hand-wash and wash around the holes, if you really want to put that much effort into it)
