The only way to get better at something is to practice, Practice, PRACTICE! Great place to do that is at https://hack.me/.
Hack.me is a FREE, community based project powered by eLearnSecurity. The community can build, host and share vulnerable web application code for educational and research purposes. It aims to be the largest collection of “runnable” vulnerable web applications, code samples and CMS’s online. The platform is available without any restriction to any party interested in Web Application Security.