• Start participating to Bitcointalk forum, aim for good forum posting and nice forum post count. Once you achieve "Member" or "Full Member" look for a good signature campaign, and start earning Bitcoin.
• If you have a talent, or good in writing, then do freelancing! Post your service campaign to "Services" section of this forum. And earn Bitcoin money.
• Learn how to trade bitcoin. Trade with caution and do it wisely. This would make your Bitcoin money to double or triple.
My 2 cents
Newbie, they can grow their accounts and enrolling into a signature campaign. With skills you can do freelance as you said or offer some service or maybe trade some goods here.
For expert, signature campaign is not enought. Many members here have their ways to earn bitcoin, by trading or gambling or anything else.