Activities that can help in improving active vocabulary are avid reading, playing word games and making notes of new words. Frequent use of the new words helps memorize them more easily.
One good way to improve vocabulary is reading as often and as much as possible, and making sure that the reading material is interesting and a bit challenging, containing words that are not familiar. The texts should be on various topics and as exciting as possible. If the reading experience is enjoyable, the memorizing process is significantly easier. Looking up words that are unfamiliar and making notes of them is also useful. The notes should be revised daily.
Playing word games is another vocabulary-building activity that is rather efficient and fun. Games such as Scrabble, or crossword puzzles, played and solved alone or with friends, are helpful when attempting to expand vocabulary.
When learning a new language and trying to build vocabulary, it is always a good choice to listen to music or watch movies in that language, either without subtitles or with subtitles in the new language. This is both fun and useful in terms of learning new words and becoming familiar with their pronunciations.
It is essential that the new words are pronounced correctly. The pronunciation of words can be found in a dictionary. Some online dictionaries, as well as sites such as HowToPronounce and HowJSay, contain audio recordings of words and phrases, which is rather helpful.
The most important aspect of vocabulary-building is frequent usage. Everyday usage is the key to keep words fixed in long-term memory.