Some of the best ways to learn English include being in an English speaking environment and practicing every day. The best way to learn is through speaking the language.
To improve in the language, work on the four core skills of reading, writing, speaking and listening. One way to practice includes keeping a notebook of new words to learn. Use them in sentences throughout the day and try saying them three times when speaking. It is easier to remember words by remembering an example sentence using that word rather than remembering the word on its own.
Long term and short term goals are also valuable tools. When reaching a goal, earn a reward. A student does best when he knows how he learns best. For example, he may learn through memorizing, reading, speaking, summarizing or other methods. He may work best alone or in groups. Using those skills in a way that is catered to the student will lead to the most success.
It is also beneficial to review words and ideas repeatedly. Revisit things studied in the past. Don't be in a big hurry to move up a level; give the current level time and attention to fully learn.