I was inspired by a couple of ideas I found on pinterest.
First we made our own "puffy paint" combining equal parts flour, salt, and water (we used 1/3 cup of each to make about 5 oz.) and then mixing in some liquid tempera to color. The children chose to make red, purple, and orange. I then used a funnel to put the paint in small 2oz squeeze bottles.
I then set the kids up with some white cones I had made from cardstock and trimmed so they would stand up straight. I also taped them to a base to catch spills and keep them from tipping over while they were being painted.
We ran into a problem right away. The paint wouldn't squeeze. I found a small pair of embroidery scissors and managed to make the holes larger and that worked for a while. We continued to have trouble during the activity with the holes getting blocked by small lumps of paint or because the paint dried up in the tip. We would shake and tap the bottles and I'd use the scissors to clear out the tips of the bottles and that helped. I honestly think the children would have played much longer if we hadn't had the technical difficulties though.
My only suggestion would be to use squeeze bottles with much larger holes than ours - perhaps ketchup style holes. Or just use a paint brush.
They had a blast though. From the start of the project (making the paint) through then end of painting the cones, the kids were engaged for a full hour and a half.