Im into vector art, and ive doing some of them since a year ago. was wondering if you guys can give me any tips or hints to improve my vector. I have an acount on deviantart so if you also have a dA acount please comment else wise, comment here please, thanks heaps.

Old vector

Tachikoma vector - http://www.deviantart.com/deviation/40737600/?qo=15&q=by%3Acnc-mrudon&qh=sort%3Atime+-in%3Ascraps

Alphonse vector - http://www.deviantart.com/deviation/40737022/?qo=16&q=by%3Acnc-mrudon&qh=sort%3Atime+-in%3Ascraps

New ones

Vash's Gun vector - http://www.deviantart.com/deviation/44256038/?qo=4&q=by%3Acnc-mrudon&qh=sort%3Atime+-in%3Ascraps

Kenshin vector - http://www.deviantart.com/deviation/44379916/

Jin vector - http://www.deviantart.com/deviation/51869017/