Speak without fear. Learning the English language won't be without mistakes. But the only way to know they are mistakes is to make them. Gather a group of friends or an English speaking neighbor, and make a little party out of it. Only English will be allowed and when surrounded by others who will likely make mistakes, the fear will become a non-issue.
Pool your resources together and surround yourself with the English language. If you currently live in an English speaking country, try joining a club that captures your interest. In this way, you will not only be interested in the topic itself, but you will also be immersed in the English language. If you live in a non-English speaking country, find an international club where the language is predominantly English. You may also want to consider having a pen pal from an English speaking country to practice your writing skills.
Watch English movies and listen to English music. Learning the language does not have to be mediocre. Watching English movies will help you pick up on English slang that you ordinarily would not learn in a classroom.
Take practice exams or self-evaluation tests and study often. As with any academic subject, the discipline of study is a crucial element to success. These assessments will help you to understand where you stand in terms of skill and which areas you need to improve upon, whether it's auditory or written.
Record yourself speaking the English language and compare it with the English movies or music you have been listening to. This will help you to evaluate your pronunciation and accent.