Most of the time there are official events, so you can actively participate in them and get free tokens.
Most of the time, though, the amount is not particularly large.

I doubt you will get some merits because many have told the same infomation over various bitcoin forums if merits part of your plan to share (many have tried and failed too) but still I do appreciate that you are giving this information for the consumption of the newbies.

All suggestions you mentioned are the way of getting free coins or tokens. But do you really think it is that easy? Do you think the value of those coins will actually rise extremely high? They are given away for free, so chances are that they won't. And bounty, airdrop and quiz/giveaways are actually not really worth it if you are a serious investor. They are just waste of time. You could do something more efficient to earn more using the same amount of time and concentration.