Recommend to everyone to know the rules of their 401k match.
I thought I would be smart and only contribute to the 401k during bonus time, zero the rest of the time. While previous companies let me do this, unfortunately the rules of my current 401k plan meant that I had to contribute at least the minimum for each paycheck to get the full match. You can imagine how devastated I was when I lost out on the free money. Now, while I still make huge dumps during bonus time, I never go below the minimum the rest of the time.