By inmediately incorporating them into your speech. Try to use them as often as possible; some words have many alterantive meanings, so you can explore them all if you use the word often. :)

To use them as often as possible.

I think the best is to practice in a trip, or online with a friend. Sometimes you say the perfect words, but is not like the local people would answer. When you practice it with a friend or in a trip, you get noticed that there are "patterns" in answers which you can consider instead.

One example (very short, because I still learning) is like: Where is the party today?
1- It is in Betty's house.
2- it's in Betty's.

It's very important to me to pray attention in the video or personaly where I can watch the mouth and faces... it's far better to completelly understand.