Thank you for starting this interesting chat topic. Here is what I think:
If you want to be able to actively use the vocabulary that you learn in your own writing and speaking, you must learn it in context and as part of a phrase, not in isolation or through translation. The best way to access vocabulary like this is by reading and listening.
The choice of what you read and listen to depends entirely on what type of vocabulary you need in your daily life and your interests. Thanks to the Internet, you now have access to written and spoken English on any topic under the sun.
One thing we must never forget if we have learned new words through reading is to check their pronunciation in an online dictionary. Never guess how a word in English is pronounced!
I'd love to read everyone's opinion, experience and suggestions on how to expand one's vocabulary range.