Indeed, need to be wiser in terms of decisioning, not just the money but all the efforts that you put in working with strategy or plan that you made when playing, always be the best decision is to quit while you are still at green, whatever the amount as long as you gain from your initial deposit that's still consider as profits, better than losing your chance taking your earnings out from your gambling activities.
In order to withdraw winnings, you first need to make sure there’s something to withdraw. Yes, you’re right when you have profit from your deposit, you should take it out. But it’s also important to stop not only when you’ve secured a good win, but also when you’ve had several losses in a row. That’s a clear sign that you need to stop and take a break, so you don’t end up losing even more.
Some people have a target amount they want to win before they stop gambling for the day and if they haven't fulfil that target it is always difficult for them to withdraw the little profits they have made. Though i don't like the idea of setting a winning target because i believe that inasmuch as you are able to increase your deposited money, regardless of how little the profit is just take it out and probably continue next day or next time but greed won't allow most gamblers to employ that strategy since majority of gamblers are interested in huge wins.