You may follow the site
https://airdropalert.com or you may go Signature ads bounties section or in announcement alt coin thread, Make sure you have accounts on social sites like bitcoin account, twitter, facebook, and telegram because these are usually requirements to join the airdrop. Wish your luck in joining airdop:)
That's good news for airdrop hunters. I was looking for such websites where people are informed about new and upcoming airdrops.
You can also check the forum and make a quick research on this to find new ones.