If your wallet is encrypted, make sure it is unlocked or you won't stake.  When I first setup my wallet, I didn't seem to stake much at first either, but now I get 2 to 6 stakes per day.

The stake is also based on each individual transaction.  So if you only have one transaction to your wallet, that is the only one that can stake and it will take a while.  I have a bunch of small txns, and they each stake at their own interval.