The claim process differs from project to project. Some “holder drops” will drop tokens automatically into the wallets of users who own a specific coin. Other projects are snapshot- based, and can only be claimed by users who held the required token during the “snapshot,” which is a record of token holders taken at a specific time/block.
An example of a holder airdrop is Byteball, which was initially distributed to Bitcoin holders. They also airdropped a monthly amount of Bytes into the wallets of Byteball holders proportional to the amount of BTC/GBYTE that they held during the drop. These types of drops can create excitement which often results in significant price action for the particular coin.
For taking part in bounty airdrops, you will likely need active accounts on social media sites such as Facebook, Twitter, and Telegram. You should also have a Bitcointalk.org account, as some drops require participants to post proof of ownership in the forum threads. Most bounty drops will require you to join a Telegram group and share posts on Facebook and Twitter. After completing the steps to reserve rewards, you will often need to fill out a form with your usernames and wallet address.