I would suggest to you to try the trading and joining a signature campaign in this forum. In trading you must know the basics on how to trade. If you are familiarize in trading you will get a huge profit. In signature campaign the higher rank you are the higher payment you get.
Yeah, that's one of the best options imo. Join a sig campaign, research, make substantial posts and you'll be earning Bitcoin little by little. Of course this advice is for people like me, for whom additional $200-$300 per month makes big difference. For people who have a lot of money I'd suggest to buy as more BTC as they can afford.