Repetition. It's really that simple. (1) Get an understanding of how to make the sounds from native speakers. (2) Make a list of all the words you know you d

Repetition. It's really that simple. (1) Get an understanding of how to make the sounds from native speakers. (2) Make a list of all the words you know you don't have a good pronunciation of. (3) Repeat the words to yourself regularly. That's it. Some words will come easier than others, and ones you have mastered can be removed from the list. I find it's best to do them in small blocks. Five at a time, or whatever you can easily hold in memory.