"No, you don't have to answer

the question but if you don't answer the question then don't complain if I can't do the job or I do it in a way you don't like."
Right now I want to scream that.
I am endeavouring to be fully prepared to do something to help at an event tomorrow. The event organiser I have been communicating with has been really good. She has her hands full trying to get the thing to come together. I suspect it has been more work than she realised it would be - isn't that always the way? I have no arguments with her.
The person I am going with has been really good. She emailed and phoned me earlier in the week.  I know she will pick me up at the stated time and that she will prove to be an equally reliable and able co-worker. Spending a day in her company will be no hardship.
No, it is other people. 
I have items for another stall. They are a donation, not being placed there for sale for my benefit. It would have been useful to know how they wanted them packaged and labelled. I have ended up packaging and labelling them without any guidance. I'll just have to hope I have done it the right way. 
Yes, I know that the people running this stall are volunteers too. I know they are busy. The problem is that, had I been told what they wanted,  I could potentially have saved them time rather than added to what might end up being a pretty fraught early morning setting up. I know very well what is expected of people putting items in for sale for their own benefit. I could do that as they expect but I'd really like to save them problems and do the rest the right way too. It has taken me two days to pack up over 200 tiny packets. I am passing on things that were given to me that I would love to have been able to use but realistically never will. I want other people to be able to use them instead. 
I just wish that someone had said, "Yes, do it that way Cat."
It really would help!