Have you ever heard the ages-old expression, "Practice makes perfect"? This can apply on some level to anything in life. For Japanese, however, there is no perfect. Practice will never make you perfect in Japanese because perfect Japanese doesn't exist. Aiming for perfect is the same as aiming for nothing. Aiming for perfect is aiming for failure. Practice will, on the other hand, make you better.
This especially applies to kanji. Specifically, writing the kanji. I've emphasized this before, but when doing kanji reviews, time should be taken to physically write out the kanji on paper. Not only does this make it stick better in your mind, but it also improves your Japanese handwriting.
The photos in this post include some of my kanji practice, both in sentences and individual. My practice sessions also include hiragana and katakana, as these are quintessential to Japanese reading and writing. These sessions are going to be changing up somewhat soon, as I'll be migrating over to using MCDs soon so I don't have to write an entire sentence every time it comes up.
I know my handwriting in these examples needs a lot of work. Believe me when I tell you that it is far better than it was when I started, and will continue to improve as I practice.
Aim to get better, not to become perfect. Aim to improve your Japanese.
Hit the target by practicing - constantly.