How do you hand money to a cashier?

So I'm a cashier and I have always been very annoyed and disrespected by the way people hand me their money . My coworkers also feel the same way and I want to know some opinions on the subject . What I'm referring to is when I check a customer out and they are getting their money out for me instead of handing me the money which is the respectful and appropriate way to do so they will put the money ( bills and change ) on the counter for me to pick up instead of handing it to me . This is disrespectful and ignorant like they're afraid to touch my hand or something but I'm not allowed to do that to them because it would be a problem . So my question to everyone is when you give a cashier your money do you hand it to them or do you sit it down for them to pick up ? && if you are the one that puts it down. what is your reasoning for it and has anyone ever told you that it was disrespectful ?