First things first! Why you need to memorize english words? A- To write better B- To improve your conversation if your answer is letter A, i think the best way to memorize is writing your thoughts, ideas.. if it's letter B, you just need to know the meaning of the words...

Hearing the language spoken by NATIVE speakers and speaking with them (native speakers only). Reading helps too but it’s slower for some reason. Using the language, even talking to yourself (even out load is not the sign of mental illness, in spite of popular ideas to the contrary. Everyone does this). Replace your native language with the target language. If need be, learn to research words for their correct application, and carry an online pocket dictionary on your iPhone. Consider you native language only a bridge at best to the new language and an enemy of your target language. Because it is. It does and will interfere with your vocabulary building and speaking in every way imagineable.

I never memorise. I hate the idea of it. I keep reading and keep seeing the same words. Eventually, the meanings stick.