The one and only safest Method is FAUCETS. No investment, No Risk, No Tension. There are lot of Faucet rotators to simplify your job.
it's true but you should take into account the fact that they are not so productive in terms of profit, you need a bot at the very least to be profitable, and i can't find one for now
otherwise the reward is around 0.002-3 per day if you work 4-8 hours with many good faucets of 1k satoshi each
Yes spending time on these faucets is not so much worth, you may get maximum 0.001 to 0.002 maximum for one full day instead you may consider to joining some good signature campaign. If your english is at least decent with signature campaign you can surely can earn decent bitcoins per week compared to faucets.
If you want to further grow your coins then consider peer to peer lending and it’s basically the idea of lending someone Bitcoins and getting them to pay you back with an interest. Here you can earn around 10 to 15% profit on your investment per week. Remember not to loan any strangers with out any proper collateral.
Other option is trading but it is not for newbies - you should have a good knowledge of trading because the exchange rate isn’t a volatile as it was a year ago hence it’s getting kind of hard to actually profit from just buying and holding on to your Bitcoins.
trading with bitcoins grows more bitcoins. 
