Some good advice Arlyn and Bonnie some very polite ways to get your point across.
I have violated some of the rules, like putting a for postage check aside and forgetting to cash it for a long time. or stuffing a box full of extras because I want to get my moneys worth on the flat rate box.
I think most people expect a few extras and are good about telling me if they'd rather not have many or any. It's hard to know what to send people for extras though, as I don't always know what they have or want. I do keep files on all of the boxes I send, and what was in it, so I can TRY to avoid duplicating extras to some degree. Although I have somehow deleted a couple files by mistake and that is not nice.
The biggest problem I've had, and only once, but it's really annoying. I had a visitor come during bloom time and spend a lot of time listing all of the ones she wanted. We worked out what the price would be, and she was fine with it. It was a rather large order. Then I called her to set up a time for her to pick them up and pay for them. We set the date, I dug the irises and she never showed up. Called her back and she said she had an emergency and could she pick them up at a new time we agreed on. She never showed up, and then didn't answer calls from me after that. So now I've spent 3 hours digging, washing dipping, naming, irises, and have to go replant them all. I was not a happy camper.
One woman called at 9:00 at night to answer my Craig's list ad for irises. I think she was just a lonely, bi-polar person from Chicago who talked non stop about everything she had including about 6000 acres of land in Wisconsin. I couldn't get a word in edgewise, but finally I asked her what time she would like to come and get the irises. We set up a time and of course she never showed up. This one I never expected to see.
There are some really different people in the world, and not all of them define "common sense" the same way