Airdrop is the easiest to get coins for free.
So, you just need to be careful if it's sent via e-mail about notification to click or something like leading to phising, etc.
You keep filling the form of airdrop and just holding until the time you need to withdraw or use the coins, then when you open, it makes you shocked. The price is so high and you get tons of it.
Just holding the coins from airdrop, sell when it's really high. Because holding tokens is the best way to achieve high profit. Always there will be one gold between all of the coins you get. I've ever experienced about this.