I was on the PTA for the whole time my DCs were at school. I ran it in the end and had some golden rules I stuck to eg money raised had to benefit all the children in the school not just a small group eg musical pupils so that parents could see the benefit to their own children. The exception was that we ran class cake sales where each class took turns but then their cake sale money was spent on their own class.
Another thing I thought important was that at the big Summer and Christmas Fairs I had one volunteer on making tea for all the volunteers.
In the end it is worth looking at effort per fundraising activity and the amount of funds raised. Some are not worth it and some are very low activity for good funds - here I would include a beetle drive, 100 club, clothes recycling, non-uniform days, teddy bear tombola.
Getting help involved a serious letter to all parents explaining that without help the PTA would fold and pointing out all the recent things that had been funded.
Not everyone likes to run a stall but maybe they are graphically skilled and can make the posters and put them up, or do the shopping for a bbq, or wrap lucky dip presents etc.
A big notice in the playground helped with specific jobs and times and a space to sign up. We left it up for parents calling for children later (those in homework club)
Don't always ask for money. Clothes recycling worked very well and non uniform can be 'paid for' with a bottle for the bottle stall - not always wine could be shampoo or tomato sauce etc everything welcome. Another time we asked for unwanted tolietries and made up pamper hampers to raffle.
Finally I do think it is important to have a chair that is easy going and values all contributions in whatever form and does not put people off.