I stopped here to answer your question, but I think dahoglund has answered it better than I would have done. But to summarise:
1. Be open to knowledge
2. Read with an eye of a writer
3. Try to understand what the other writer is trying to show what is deep hidden into the rumble of words (this will increase your overall writing skills and creativity)
4. Learn some basic English Grammar Rules
5. Learn the differences between some confusing words like accept vs. except, affect vs. effect (I have several hubs on this, you can check them out)
6. Do some exercises in your spare time. This will be a learning process and gradually you will master it.
7. Write! Don't forget this point.
Happy Hubbing! Have a good day.