I love my local animal shelter for being able to use almost whatever I knit, including simple shawls, which they sell at the fundraising events and "open doors days". Very delicate, complicated shawls are not suitable, because due to the amount of work and material they require, they would cost too much for the audience generally visiting the events. Small shoulder shawls, made with less than one 100g ball of sock yarn, using a simple stitch pattern however is the perfect product - useful, beautiful even though simple, and more interesting to buy than a pair of socks for example!
This is my latest Tierheim shawl, with a very simple stitch pattern and self dyed yarn.
Pattern: Tierheim shawl 2, of my own making! I plan to publish this little pattern soon
Yarn: nameless self dyed (by me!) yarn given to me by a friend. I assume it's sock yarn, at least it's the same weight.
Needles: 4mm circular used as a straight one
That's a lovely shawl! Charity knitting is great, but like you said, it's hard to know what to do, as anything too elaborate won't make the money it deserves.