Memorizing is about review. The more times you review something, and the more ways you review it, the better you will remember it. So, if you memorize with flashcards, and then try to use those words to write a notebook, and then read an article with those words, and then try to use them in a conversation, etc. These kids of activities will help you remember more of what you study. Also, I like to memorize sentences when I memorize words. I like to use http://tatoeba.org/eng/ to find example sentences from the web with new words that I've studied. You can type in a word and a language, and it will find sentences for you! This is also a good way to learn similar vocabulary, which is another good way to remember, by grouping your vocabulary together.

you should read when you are free. and speak with someone for remembering them

I think the flash cards are a good idea, but not to learn. They are mostly useful for identifying words that you "think" you know, but really dont know too well. It helps you find your weakness.

I think learning words does not require memorization. You must use your mind more efficiently to learn. You will notice when studying, that some words you will remember very easily, and some words are harder to remember. An unusual or cool sounding word you might remember very fast, but others do not seem to stick to your brain. You must figure out which words are harder to remember and focus on those. Once you identify those you should try to think of similar words that will help you remember these more easily. Also you should sometimes point to an object that the word means, and then it will stick more. Try to associate ideas , pictures, or other things to recall the harder words. Also what might help is learn groups of words at once and memorize them all at once. What I do is sit down and learn 30 words in one hour. Then I review those words, I will notice that about half of them are harder to remember, so I focus on those ones more and I try to compare those chinese words to english words, or I try to find patterns in those words which help me to remember them. Hope this helps!

you cannot improve any language inside a classroom. The best way to master any language is to make that language a part of your life. You use your native language all the time isn't it. Just like that try to use the language you're learning as much as possible. There are lots of interesting movies, tv shows and other materials. And read stories, magazines, articles whatever you can find. As you do this you will randomly come across unknown words, look them up on dictionary. If you do this way, you will remember the words much easily. And remember memorizing words straight-away won't help you much if you don't use english often.