The logic behind slow playing is to make your fellow players or player believe that you have a worse hand than he has and you are simply uncertain on what to do. It can be a good way of playing
against either novice or professional players, that being said you will find novice or bad players will simply bet on any hand.
Usually it's not the best policy to slow play when there is a draw on the board, you ideally want to slow play when someone has a hand that has a low chance of going to
improve on the hand you have, an example being when the board is showing an Ace Nine and Five and you are hold two 9's and you are confident they have an Ace, it is much better to wait until the turn to start betting hard so you can draw
more chips out of them for possibly one more extra bet.
Always try and change your playing style so your opponent can't get a fix on you, do this often during a game. If you have noticed you play strict or even loose then try and sometimes do the opposite
This tends to work best in no limit games and the short handed types where playing the bluff is useful