I was involved in an Art Auction a number of years ago which actually raised a lot of money for the school. But what they did was to contact local artists and ask them to donate a piece of art to the school. They then advertised the Art Auction and included pictures of the professional artist's work in the ads (brochure or postcards). This was a huge draw for the community. Some of the parents volunteered to provide snacks. It also is very exciting to watch people biding higher and higher for these works of art and to know that the school is benefiting. If anyone is interested in doing this let me know and I can put you in touch with artists willing to donate work.

Our school has done one for years.
Walls are lined by parent volunteers with paper in the cafeteria. Each classroom is giving a specific space and dimensions to fill. That's for flat artwork. Then tables are set in the middle for 3d work. There are some rolling boards that get pictures and other art hung on them, take about a week before to get 20 classrooms with about 450 kids work up. Teachers pick what will be placed there. Hold these throughout the year to prepare. Then we have this open on OPEN HOUSE night at the end of school year. We've also held a raffle that night in the past, monies go to art program. Good luck!

We have a county wide art show with all 14 or so schools participating. The art teacher of the school picks out 4-5 winners of each class. The works are displayed in one of the large schools in town. You go by, look at the art up on the walls, and leave. Yay.
Since we share our art teacher with another school (we get her one semester then she switches), the PTO decided to have our own art show. We realized that most people did not want to drive 40 minutes away to see some art by people they didn't know (except their own child's). Last December, the art teacher, with the PTO, had an Art Show. We folded up the cafeteria tables, lined them with black posterboard, and displayed a piece of work from EACH student. AND the winners that the teacher had already picked to go to the county-wide art show was displayed up front on a red backdrop with yellow ribbon.
We served refreshments: cocktail weinies in bbq sauce, crackers and cheese, and wine (Welch's Sparkling Grape Juice in the "wine" bottles).
I was happy with the results. We had more people come than I estimated and that was GREAT!!
The highlight of the night was watching the kids grab their parents' hand and pull them over to see their work.

We do an Art Night/Contest. We have each grade submit art work in visual, computer art, photography, and literature. We have independent judges view all the work and award 1st place an honorable mention in each category in each grade. The PTO chairperson picks out a theme that the students follow. The PTO has medals and certificates and a certificate for each child who participated.

Then on Art Night, we hang all the work up in our big gym, have crafts for the kids, local artisits come show their work, face painting and snacks. We hand out the medals and the certificates for those who come to art night.

This is our 3rd year having our Art Night and it is a lot of fun.

We do one every year. We put the artwork up all over the MPR walls, and using some tables as room dividers (they stand on their own). We do it on our Open House night. It opens about a half hour prior to Open House. We also incorporate a fundraiser with the show. Each child can "purchase" their artwork for $1. We give them "Sold" starburst stickers to place on or near their piece. The kids really enjoy it.

Our PTO pays for the entire art program at our school. As part of that one of the fundraisers is focused on art and we ALWAYS do an art show at the end of the year to highlight the kids accomplishments.

We normally chose one week night, normally a Tuesday or Thursday, in April or May. The show runs for about 2 hours or less. We post the art work in the hallway by the child's classroom, normally 3 to 4 pieces, depending on how/what was done. The easiest way is to put the child's name on a card at the top and all of the art work under it so it is easy to identify per student. The kids normally do 6 or so projects but normally only the best 3 or 4 are posted. There are signs put up with each grade level telling what the art is or why it was done. Last year was the first year that we gave ribbons for 1st, 2nd, 3rd place per classroom. A grand prize and a 1st, 2nd, and 3rd (I think) were then chosen from those pieces and highlighted at the front of the entrance on a special table. (They were later framed and hung in the school lobby. The ribbons are just paper clipped to the edge of the picture for simplicity sake. We normally offer some light refreshments. (Last year were pretzels, m&m's and lemonade... some years have been cakes and fruit, it varies.) And we have also started involving different musical (instrumental) artists in the community and have them come in and provide atmosphere music for the event. One year it was the kids for the talent show, another year a few kids from the high school orchestra. It varies, depending on timing, etc.

One year we also had an "exhibition guide" which shared information about the type of art, classes, etc. So that can always be another option.