These different methods you listed out is mostly the best method to earn Altcoins especially with trading,  either you are going for short or long term trading.  Trading is the most lucrative of earn bitcoin on a regular basis but also you need to have a good knowledge of trading as well to maximise your earning. Others methods like airdrop, bounties and faucets too are good ways of accumulating Altcoins, with these you need to know you will devoid alot of time to maximise earnings from them.