I'll suggest Trading with your Bitcoin or investing in Altcoin. People suggest Gambling alot, I havent given it a try though
Other Suggestions..
INVEST IN:
1.Competitive gaming
2.Gambling
3.Betting Predictions
4.Merchant Sales
trading is better than others. you can minimize the risks. in addition, it is also an investment that you can control, and I'm sure, when you're proficient in controlling it, you might be able to grow bitcoin do you have in a short time.
The high-risk level of the gambling always becomes the main concern for the everyone, because I need to mark this word, we can lose our money just on single click on our mouse, that makes the people interested in using trade to grow his amount.