1. Make a move that will maximize the number of stones going into your Mancala ("Store"). This can be quite an effective strategy because when stones go into your Mancala they cannot be taken out again with subsequent moves. Also, of course, the object of the game is to have more stones in your Mancala than your opponent, and this "direct deposit" method works toward that goal.
2. Choose a move that will allow you to take another move. That is, have the last stone in the move lands in your own Mancala. This strategy allows you to add stones to your Mancala on more than one go, but this may not be the best strategy if it will empty your side of the board too quickly (thus allowing your opponent to score all of the stones on his side of the board).
3. Make "defensive" plays. That is, if the opposing player has empty pits on his side and, thus, has the chance of capturing stones on his move, make a move on your turn that prevents your pieces from being captured by moving stones into the opponent's empty pit. This strategy might not be the best move in terms of maximizing stones going into your own Mancala, but it can stop your opponent from capturing stones (which helps towards winning in the long run).
4. Set up a capturing move for your next turn. You can empty a pit where the opponent's opposite pit is not empty and where you have a pit before it that, if chosen on next turn, the last stone from it will land in that empty pit you created on the previous turn. This will allow you to make the capture and collect all of those stones.