Something that usually helps me is to try to use those words as soon as possible in a lot of different examples. This also works with new grammar structures. Writing the word or words down is also something that works a lot for me. Writing helps me keep things in my brain but speaking helps me understand a little better. If you learn a new word in a class or with a friend that knows the word be sure to use it in that class or with that friend. That way you can start with a good understanding rather than if you use it much later.

I found myself learn and memorise vocabs in any languages better by finding correlations of words. Like GLASS is a cup which doesnt bend so it goes with a "L" whereas "GRASS" moves so it is with a "r". The grass does look like an "r", doesn't it? :)

I write the words many times and then test myself.