I'm ruthless with my money, even with regulars. I work from hotels now so there's nowhere to hide, I take it off them within 2 minutes of them walking in, check it in front of them with my pen and put it down, but still leave it in view. I think if I was going to get robbed I'd rather they just took that money back rather than hunting about looking for my hiding places (they probably would anyway but just makes me feel a bit better), I hide it once they've left.
I get loads of regulars in a huff about me taking it up front and checking it, one in particular says each visit 'do you not trust me?' No I don't. I don't care if it offends, it saves any confusion or underpayment, or even overpayment.
Had too many clients trying to pull a fast one in the past so I won't change my ways.