I don't there is any shot cut to make money in short duration.
You can invest in the cryptocurrency,but right market is going very bad phase.So there is no guarantee to make profit in short duration.
Safe and reliable way is bounty program of BITCOINTALK forum.You should join the different bounty program like Facebook,twitter,blog writing, video etc.by this way you can make 500 dollar in 3 month.

And last ,if you post something good and quality in this forum ,you will get merits for that.By which you are able to upgrade your rank ,that will be very useful in signatures bounty of this forum and you can earn money... higher rank will give you higher share of stakes....

Good luck