Try to put pressure on your opponent so that he makes weakening moves that cause his position to deteriorate.
Self analysis
If you have sufficient positional knowledge, then you will be able to differentiate a good position to a bad one. This way you will never run out of plan because no matter how dull the position is, you can always try to make your position better than your opponent's.
And I always pay attention to endgame very early. This is often the secret to win many positions (even tactical ones). Just make sure when you drop pieces for example, you will have the upper hand in the endgame (e.g. because you have favourable pawn structure). Many strategy can be based upon endgame knowledge.
So today I think something clicked inside me and made me realize what is probably my next step to increase my rating. For the last year I've been learning a lot but I just can't seem to pass the 1200 mark. Then I said to myself what is making me win and lose at this time. And I think it's the fact that I am playing positionally well up to the middle game and that I can start taking advantage and win when the opponent blunders. However, if the opponent doesn't blunder, then we can go to an engame( assuming now I don't blunder) and then it's either me or my opponent. So I guess what I'm saying is that I think I need to now think about a plan or strategy(with tactics in mind) after the opening where the position is equal and ask myself, ''what can I do now to increase my advantage ?''. I would like to hear from other's around 1200-1800 if this is your case as well. Are your games won based on your opponent's blunders or your thinking process that enables you to take advantage even when the opponent hasn't blundered or played well ?