Build up a 9 month fund of your fixed expenses (mortgage, food, car payment, etc). It can be quite liberating to have a "Fuck you I don't want to work here any more" fund. I did it by laddering some CDs. Go ahead and get the 5 year term so you get the higher interest rate. If you have to cash it in early, the typical worst case is that you'll have to give up 1 or 2 month's interest.

Ally bank is currently paying 1.5% on their 5-year CD, with a 60-day interest penalty for early cash-out.