Optimizing gas fees for airdrop token exchanges involves several strategies. One is to batch transactions, reducing the number of individual transactions and thus overall gas costs. Another is to choose the optimal time to execute transactions when network congestion is low. Additionally, using layer-2 solutions can significantly lower gas fees. For example, on Ethereum, Optimism or Arbitrum can offer lower fees compared to the mainnet, facilitating more cost-effective token exchanges for airdrop participants.