Use Anki on your computer or smartphone.

Try to use it often in your daily conversations and / or relate it in your mind to something you will remember. Think different examples of phrases that contain that word. :)

Write those words you forget on a big paper, place that paper in your room where you can see everytime, I'm sure you wont forget after some time : )

Repeat it with short pace and then with long pace.

I suggest reviewing the vocabulary several times. New words often come in large quantities with learning new languages, and it is not easy to remember them all at once, fluidity and being able to remembering words faster comes with a lot of practice. Also, in my experience, words are specially easier to remember when you learn them in context, that is, if you are studying a topic in particular, and you are able to see how words are used, and then practice using them (playing with the words, making up new sentences using them and then have someone else correct them), then you will internalize such words meanings and you will not forget them so easily. This way, you will be able to remember many more words than if you simply learned lists of new words that do not really bear any meaning to you.