I have tried faucet and they are such waste of time don't bother with this if you don't have some kind of bots..
Signatures are good, but you are on risk to become spammer..
Trading and gambling is very risky. Only what stay is doing something useful for coins..
there are signature campaigns that don't have any minimum number of posts requirement or it is very small for one week so you don't have to spam.
and i agree that the best option for earning bitcoin is doing something useful like some freelance jobs if you are into online works like programming or graphic work.
Yes signature campaign is good to collect some coins, but you can always find various ways to earn bitcoin totally depends on what skills you hold and what services you can offer.