How do you actually get new vocab to stick?

I've been trying to link new words to grammar structures I already know well, instead of just repeating them on flashcards. Like if I learn a new verb, I try to force it into three different conditional patterns to see how the nuance changes. It helps me remember the word way better but it takes so much time. How do you guys stop new words from just slipping out of your head after a day or two?