You want to express yourself? But you don't know. You think you're going to say something sounding like English but it's far from the simplest. You decide to shut to avoid embarrassment. You don't worry "a fighter never quits".
So here are the tips:
Make reading your sweetheart.
Yeah you have to love reading first. Read more books, newsletters, magazines... go online. But don't just read, make sure you you mark some words from the context then check their meanings from the dictionary. Be dictionary friendly.
Create a logbook.
You put down the new words that you've learned in this book so you can refer later.
Learn a new word everyday.
Make sure that you've learned a new word everyday, how it's pronounced, spelled and how to apply it in a sentence.
Engage in a conversation.
As I'd said, " a fighter never quits" Don't shy, just engage in conversation with other people and make sure you you use the words you've learned as well as putting the new words you hear while chatting with your partner.