Besides trading, are there any good method to earn bitcoins? Thanks.
There are many ways. If you like this forum, you can join signature campaign and earn from them, or you can sell some things here for bitcoins. If you feel lucky, you can try your luck in gambling, but i have to warn you that it is pretty risky. If you have bitcoins, you can create and own gambling site. Or, if you have time, you can try to trade currencies. As you can see, there are many ways to earn, i told you few only, it is up to you what you will do.
Trading is good only for those who are old in bitcoin world as they have been learning it since long time but for people who are still new they can start earning it from signature campaign and by offering services which involves zero risk.