Look at the background of the project. Do not just immediately jump into it because it is giving away free coins or tokens. That is not important. What is important is that your coin or token has worth. So instead of using your entire time looking for an airdrop all the time, focus on reading the project's whitepaper or their website. You have to know whether the project is composed of a credible and experienced team, whether they already have existing partners, whether they have the capacity to launch a crypto project. If they pass all these, then join.