Speak.

If you meant speaking and pronunciation I would recommend listening and reading outloud.That helps me a lot. When we speak, the first thing our pronunciation depends on is our "ear memory". We should make our ear to listen to a lot of English to memorize the proper sounds. Then we should read outloud trying to connect our ear memory with our mouth. So, whenever you're reading a book or something it's better to read it outloud mastering your pronunciation.

Practice makes improvement. Grab every chance to talk and talk, listen and listen. 1. Watch/Listen to English programmes (TV, radio, youtube, etc). Documentary programmes are easier to understand. 2. Talk in English whenever possible eg offering help to tourists. 3. Find a language partner on italki / other channels. 4. Have lessons with the teachers on italki / other channels. 5. Listen to audio books. 6. Other ways you find comfortable to practise your oral skills. Start now and you will achieve your goal with the effort you have paid.