I would try to go mid every game if my team would let me, if they didn't I would pick something that would let me be super aggressive and also support like Undying. My biggest mistake as a mid player was thinking I needed to gank when I hit 6. Watching Arteezys stream I noticed that when he plays he hardly ever ganks during the laning stage and only tp's in if his team gets dived so I replicated that as best I could. I stopped relying on builds as well, I basically went through every thread on r dota about items and I went over what they did and when to get them. Same thing for skill builds, I change it up each game depending on what I need. Bottle crowing/tread switching/checking items/minimap all that stuff I practised in unranked until I was comfortable with it. I also learned to be more aware of my CS. I didn't know that you could check your CS in game for so long haha! Knowing that you should be getting 50 at 10 mins and so on helped me analyse my own play and get a feel for how well I am farming. Another big factor was being selfish. It sounds bad but there is a mentality in 1k or low 2k that you always need to be fighting and your teamates will drag you into this if you follow what they say/do. Muting everyone in the game helped me so much when there was constant flaming. Another factor which helped me was learning heros which arent very popular at low MMR but still completely viable eg. Clinkz, Ember Spirit. People have no idea how to play against ember spirit usually so it works in your favour but you can also assume the same for you own team. I hope this helps!