Tips:
Ears - Do fluff and inside of ears
Head - Less oval-like
Fur - DEFINATELY not as much fluff, it looks really scraggly if you do that. Make the fluff spaced out and such.
Whiskers - Make sure to have them a real size, and use size 1.
Eyes - When closed, make them down instead of up. Don't add eyelashes.
Nose - Don't connect to mouth, smaller and away from eyes.
Mouth - Away from nose, don't connect with a line. Don't do that weird w thing without edges, it looks bad.
Legs - Make sure to have them longer, and have all four and not just two. Show the muscles every cat has.
Body - Make it long, and not like a circle or something. Just, look at the difference between mine and yours.
Tail - Have it going down, most cats don't have them up all the time. I live with 12 cats, so I know a lot about their shape and look.
I hope this helped, and I wish the best of luck with your drawing!