I didn't contribute my first 3 years out of LSU around 2004-2007 since my company didn't match. Bad choice on my part but oh well.
2007-2010 I contributed 6-8%
2010-Present. 8% for a few months, then 10% for some months then 15% for about the past 6.
I'm married with zero kids. I say put in as much as you feel you can.
Edit to add, after the 1st gig 2nd company matched 2% and the current is 3%.
This post was edited on 1/2 at 7:35 pm