Things about learning languages that polyglots have in common:
- Don't wait to be taught. Be an active learner, not a passive one. Take the initiative to learn. Try different ways and find one that works for you.
- Have fun doing it! Enjoy the process!
- Have a lot of contact with the language. Get exposure every day at every opportunity.
- Learn in lots of little chunks instead of one or two huge cram sessions a week. Practice in little chunks.
- Have a system or a plan. Follow the plan.