Getting stung by a bee or wasp is certainly not fun, but you can lessen the severity of a sting by removing the stinger with a credit card instead of tweezers.
Tweezers are a common tool for removing stingers, but what many people don't know is that removing a stinger with tweezers will inevitably squeeze any remaining venom that's left in the venom sac into the skin. This causes even more pain and swelling. Instead, take a credit card or driver's license and scrape the surface of the skin with the edge of the card. The stinger will catch onto the edge and gently be lifted out of the skin.
However, the best thing you can do for a sting is to just remove the stinger as soon as possible, so if you don't have your wallet nearby, but can quickly grab some tweezers, then go for it. Just try to grab the stinger right below the venom sac to prevent squeezing it if you can.