You must always try and add tricks and lets say dishonesty to your game in order to stand a better chance of not getting read by the other players.
If you always check when your hand isnt great, but not as bad to fold, and if you always bet or raise when you have a very good hand that requires a risk then you are playing it honest all the way. And this can turn against you, because other more attentive players can figure out your game pattern and they might use their new knowledge to control your game.
When you are on the flop and you are the last or among the last players to take an action, then you can just raise the bet with a drawing hand here. It is very possible that our opponents check when the turn comes and you can also check in this case if you dont get the cards you need or expect.
However if you get what you needed you can bet as well here. The whole situation you have created this way will end up saving you money when you check and your hand doesnt become better and it will make you win a lot of money when your hand gets better. If the situation occurs and you are re-raised by another player it will cost you more money than predicted but it would be worth it because you just gained information this way about the other players hands.
When you find yourself in early position and you have a hand that should require a bet or a raise, it is better to check hoping that one of the opponents that has to act after you will bet and you can raise after that when your turn comes. This way you can get the pot much bigger. Lets say you have in hand an A and a K. When the flop comes you can see an A, a K and a 7. If you are first you will check here.
The next two players check also, but one of the players in late position will make a bet. You wait for your turn and then raise the bet that has been placed. This will cause all the other players to either fold or call you bet. But the statistics say you will get more folds than calls overall in your games. If you check and then raise when you are in an early position you get the initiative and you can control the outcome of the hand. However, if some of the other players call, this should give you an insight on their hands and it is still helpful.