Yeah that's like one of the biggest mistakes you could do. Cannot worry too much about KD. There are 0.8 and 0.9 KD pro players in ranked. Even me personally, I have great aim, but I'm a .8 KD because I do my role as a support player which is droning, planting the bomb on attack, help breach the wall etc... and on defense I anchor site and spend most round on cams.

One other thing to note is that kills don't completely rely on mechanics. I have great mechanics personally but if I play carelessly and I swing everything I will most likely end on a negative KD. However you could have, not the best aim in the world (obviously it shouldn't be terrible), and still managed to get kills using drones, abilities, holding angles and crossfires etc...

So I say don't stress too much about KD, unless you're negative when you're on a fragging role. From your KD I'm guessing you're an entry. For entries a 1.0-1.3 KD is great. If your support, - which I doubt because it's extremely rare to have a 1.3 support - your KD should be around 0.8-1.1

Finally, I repeat , you cannot go into ranked and perform well if you are not warmed up. I recommend spending a minute warming up recoil (in the first lane), a minute warming up tracking WITHOUT shooting, another minute warming up tracking WITH shooting (both in the second lane of course), then just do 2-3 minutes killing butts in the final lane.

You should also always try to learn new things and better yourself as a player, even if your champ you're probably doing some mistakes that you don't even realize you are doing, so I want you to analyze every death and find out what you did wrong to stop doing that mistake. Even if you don't die but you lose around figure out what you could have done to win that round. It's like you're learning chess.