Hope i helped! Here a some tips.
1- The Eraser and Patience are your friends. Use the Eraser to erase funky lines that wont look good. Patience will helpby making to wait to perfect lines.
2- Practice is key. Practice lines and anatomy.
3- Observe. Look at cat anatomy and how other artists use it to help them.
4- Keep in mind where the Rib Cage is
5- Limbs are always as long as the back
6- Eyes line up with nose
7- I use shapes to get the anatomy outline before i start to draw, professional artists also use that method.
^J^