It has been said many times before, the best way to earn bitcoin is to offer a service. If you have some skill that someone else could use, you can easily offer a service to others on here and earn some pretty good coin!!
There are actually 3 most famous ways that everyone are using these days for earning bitcoins, 1 is trading, 2nd one is offering services and the 3rd one is signature campaigns.
People earn bitcoins by offering their services or by joining signature campaigns and then they use those coins in trading, and when they grow their coins by trading then they hold them and wait for the price increase.