just keep playing and try to play few heroes properly that depends on situations.

me i was hitting about MMR2500 then in blink of an eye dropped to 1300 now stay there for months. but i never give up. just play and train and read all the required change log after every patch as these pateches changes the rules of the game.

as my sensei always says: there is always another higher mountain. so just do your best and dont give up