Each person learns differently, so there are various strategies that may or may not work for you. Rather than list my method and all my various tricks, I’ll suggest the most effective and long-term beneficial strategy I’ve used.
Buy the app “Flashcard Deluxe.” It costs $4, but it’s the best $4 you’ll ever spend on your education. (Available for iOS and Android)
You can download sets of flashcards that others have created (and people have already created flashcards for grammars such as Mounce, Croy, Machen, etc.) and then use them to study. The brilliance of the app is its spaced interval capabilities. Each time you get the word correct, it will increase the interval at which your word appears to study. Each time you get it wrong, the interval will decrease. So the app keeps track of how well you know each vocabulary word and works with you to only show it as often as you need to see it to keep it in your memory.
Using the app, all it takes for learning every Greek word that occurs 10x or more in the NT is to study the flashcards about 20 minutes a day for about half a year. I think by that point you will have learned all the words you need to read the NT pretty fluently. There are other special features to the app, such as the ability to add pictures and voice recordings to each flashcard, and if that’s how you learn then the app will accommodate you. But nothing substitutes for sheer rote memorization and practice. Using this app in a disciplined manner is the most effective way I can suggest to quickly and easily learn all the vocab you need for NT Greek. And of course, with its spaced repetition feature, the app will make sure you remember all the words you have learned, rather than having old paper flashcards sitting in a closet somewhere, completely forgotten.