Ask yourself weekly: What do I want to learn this week?
Asking yourself this question every week will help you stop and think for a moment about what is most important to you. It is easy to focus only on the current unit, grammar exercise, etc. If you take a moment to stop and set a goal for yourself every week, you will notice the progress you are making and, in turn, become more inspired by how quickly you are learning English! You will be surprised at how this feeling of success will motivate you to learn even more English.
More on how to improve your general approach to learning English
Quickly review important new information shortly before going to bed.
Research has shown that our brains process information that is fresh in our brains while we sleep. By shortly (this means very quickly - just a glance at what you are working on at the moment) going over some exercise, reading, etc. before you go to sleep, your brain will work away on this information while you sleep!
Other ideas on how your brain works
While doing exercises and alone at home or in your room, speak English aloud.
Connect the muscles of your face to the information in your head. Just as understanding the basics of tennis does not make you a great tennis player, understanding grammar rules does not mean you can automatically speak English well. You need to practice the act of speaking often. Speaking by yourself at home and reading the exercises you are doing will help connect your brain to your facial muscles and improve pronunciation and make your knowledge active.
More on improving your English speaking/pronunciation abilities
Do five to ten minutes of listening at least four times a week.
In the past, I decided I needed to get fit and went jogging - usually three or four miles. Well, after not having done anything for many months, those three or four miles really hurt! Needles to say, I did not go jogging for another few months!
Learning to understand spoken English well is very similar. If you decide that you going to work hard and listen for two hours, chances are that you will not do extra listening exercises any time soon. If, on the other hand, you start off slowly and listen often, it will be easier to develop the habit of listening to English on a regular basis.
More on improving your listening skills
Look for situations in which you must speak / read / listen to English
This is probably the most important tip. You need to use English in a "real world" situation. Learning English in a classroom is important, but putting your English knowledge into practice in real situations will improve your fluency in speaking English. If you do not know of any "real life" situation, create new ones for yourself by using the Internet to listen to news, write English responses in forums, exchange emails in English with email pals, etc.
More on English on the Internet