Our PTO is similar to plw's. The Executive Board sets a budget which is approved by the general membership at the first meeting of the school year. We have "Administrative" & "Hospitality" categories under which the items you listed would fall.
As long as you have presented a budget for the year to your members and they have approved it then anything in that budget may be spent without another vote. You may ammend that budget at any time during the year with a 2/3 vote of a quorum. Just make sure that known expenses are listed in your budget so that it does not need to be revisited. The expenses you listed could fall under a postage allocation or hospitality. Do you have a budget?
There is a by law section on this board or links to it and this will be a good start.
Our by laws state pres up to $100, the board up to $500 and over $500 needs the membership to vote.
This is only for amounts that are not in the budget. Meaning, if the fun night committee has a budget of $750., then they can spent up to that amount without checking with anyone. Each class has an amount for field trips and they use it as they wish until it is gone or the year ends, etc etc.
We have a dollar amount in our by-laws. (The president can spend up to $50 without getting approval from the Board.) What I usually do if I need to spend more than that, and I need to do it before a board meeting, I'll do an unofficial canvas of the board to make sure everyone agrees and then we formalize the vote at the next meeting.
How do most PTO's go about finding out how much money they are allowed to spend without going before a monthly board meeting? I am talking about, thank you's stamps, decorations, refreshments, supplies etc. Do we have the right to spend?