Well, first of all, I would focus on getting all the characters pinned down, and in different positions. For example ㄱ changes between "g" and "k" depending on it's position. I suppose the simplest, and most controlled way of doing it, is writing the words in a translator, and click the speaker icon. When you listen to that, you have to listen extremely carefully, and try to mimic it. Also watching pronunciation tutorials can be really helpful, like this one: https://www.youtube.com/watch?v=Gg-VZxBIZjo&index=3&list=PLQ-kRwgGrPgDYJeWmbn1ehAgcKyxfDWTA&t=17s And as mentioned, listen as much as possible.

When you are learning an Asian language, you need to learn vocabularies first and try to pronounce them word by word correctly. Do not try to link the words in sentences like English does. For example, when you say stop it in Korean, you have to say them separately. Stop-it. Not stopit. If you learn like this it will improve your Korean tremendously in a long run.

Listen, listen, and listen!

My opinion, dont think about pronouciation. You are not used to speak Korean. if you are used to speak Korean, it is good way to listen News and follow their script.