Step 1: Find a few friends (I recommend 2-3 Friends)
Step 2: Join a crowded 1vs1 Server with them
Step 3: Move with them together and look out for weak victims and 1vs3 them

You will notice after a few minutes that it's very hard to kill you and your friends.
I also recommend that you use Arabic/Russian/Chinese letters in your name so you can't get votekicked.

I improved from average 6/11 to 17/2

So Try it out and let me know if it's working for you!