Whichever way you choose is good actually, the point of doing it successfuly is to enjoy learning. So the best way, aside from speaking to native speakers which is the most important of all ways, is to read books, comics or whatever, something easy when you're just starting out and as you go further it has to become more complicated. The other way is watching movies, tv series, cartoons and so on. This will help you to get better skills in listening and recognizing words rather than just knowing their meanings and the way they're spelled, it also helps to improve pronunciation since you can mimic what you've heard. That's why my advice on this case is, whenever you're watching something and you hear a new word, pause the video and repeat this word a couple times to make it printed in your memory. And the last one is write short notes using new words that you've learned. It is also very helpful when it comes to memorizing.