1. Reading whatever interests you in the language that you wish you to master is one of the first steps in self learning.
2. You may not necessarily read "classic literature".
3. Just start by reading editorial columns in the newspapers/magazines/online general articles of your interest.

Note:

1. Whenever you read, you will come across many words the meanings of which may not be precisely known to you. Note such words, then check out the dictionary to know the specific meaning of the word and it's usage.
2. Then try to use such newly learnt words appropriately and frequently.

Speak:

1. Speak more in the language that concerns you (in this context I assume its English)
2. Speak to people around you and tell them that you intend to improve and excel.
3. If there's someone who can communicate well...ensure you make such a person your mentor (such mentors will point out to you on anything if you are going wrong)
4. Speaking to yourself aloud in front of a mirror is one of the ways where you develop confidence and know what you look like while you are speaking. (your can start this by reading out aloud)
5. Always remember, "it's not what you speak, its how you speak that matters"

Listen:
As important as it is to speak, it is equally important to be a good listner in order to be a good learner.
Listen to people speak in the lanugage you intend to master. You will get a good idea on how words are pronounced, used and woven into a sentence.

A fun filled way to do is : watch movies in the language you intend to master.

Improving on Grammer:
More so people are not as apt with grammatical concepts of a language. Ensure you pick up some simple elementary grammer books to help you understand the basic grammatical concepts (wren and martin by far is the best elementary grammer book available)

Pen down your thoughts:
Try to pen down your thoughts. This gives you the opportunity to write what you have learnt.
Be creative.
You could start doing so by writing a simple daily diary. (if you continue to do so, you would be able to see the improvement in your language usage over a period of time)

Practice :
All said and done, nothing can help unless you practice. It is important.

Continued learning
Never never never stop learning....remember learning a language is not simple if you dont practice and stop continued learning you may not learn enough....keep learning all along.