All options above is the common and the easiest ways to earn alts but if you're asking which method where you can obtain altcoin everyday i think doing trading is the specific method to earn alt coin everydays which is day trading manner, because joining airdrop and bounty you need to wait after ICO. perhaps  1-2 months before you receive the payment but it depends 'cause sometimes zero due to some scam project nowadays,  so much better to do a day trading if want to earn alts everyday.