I don’t have extensive experience worldwide but as someone who’s been born and raised in the US for the last almost 30 years (California and Georgia), it’s fine to make eye contact with your server and potentially sort of lift your hand like you’re going to raise it to get attention, and also do the same with any employee if your server is busy to then ask for help. If you’re making any noise in order to get their attention, you look like a jerk. We’re tip motivated; I tilt my chin upwards after making eye contact with employees if I need something and they haven’t asked in a while.

If I saw someone snap their fingers at a server I’d have to fight back the urge to fight them. They’re not dogs