Do you have trouble remembering Chinese words? I would guess not, especially for words that you use frequently. As native speakers, we all learn words and phrasings naturally, mostly without effort. More complicated words my be memorized, especially when you are at school, but there are relatively few of these. Also, we can figure out many words from the context.

Nursery Rhymes are the beginning. After that, songs help. After that a study of the "Dolch Lists" to learn the most common English words are important. Beyond that, the words studied need to be used in sentences, both written and spoken. Keeping a notebook of words used in sentences is a great benefit.

They start to learn and remembering phraeses and words from the first minutes of the birth. We can remember new words by heart only by exercise a lot and using them frequently in writing and speaking.

I found Anki very helpful to improve German vocabulary. Maybe, you will find it useful as well. http://ankisrs.net/

Also, look here: http://www.italki.com/question/277789