Does anyone have any best practices or a way of preventing duplicate serial numbers?

Use auto generated numbers and make sure that access to change or update is only with administrator or check advanced numbering suiteapp

Thank you @Nawarain, for some reason my alert didn't send that someone had commented. Unfortunately, auto numbering isn't available with serial numbers on assembly items, not a document or transaction number. And we can't limit it to Admin as personnel on the factory floor are entering builds and the serial numbers of the items that are built.