I've stayed virtual, so if they drop off or mail/ship unopened envelopes, at least I can use my letter opener and rip them all open and toss envelopes in my recycle bin and flatten out their documents in a mad flurry, all unobserved. Thank goodness, I do have lots who use my portal. I guess that's one of my criteria for firing/selling clients.
I remember a strange old lady at HRB years ago that reported me to our manager and everyone in ear-shot in the office and probably to regional/national supervisors/whatever saying I shredded her tax papers! I opened each envelope and put envelopes in my wastebasket under my desk. All documents remained in her sight ON my desk. Our office shredder was in another room, so if I were going to shred anything, I'd save it in a pile until that client was done.