I have built 2 stands for my outdoor's practice sessions. They are sturdy and standup to the wind. Many lightly built targets will blow over very easy as wind gusts pickup and it can become a pain. I am proud of the design and functionality of the two I made. Made out of 2x4's and other pine lumber with 1x2 uprights to hold an ipsc target. They are small enough to leave in the truck along with staple gun and other junk. Don't have a picture but email me if I can help with telling you what I did.
I also made a freestanding target stand like 45 mentioned, but I used 2 X 4s for the uprights. It is approximately 6 feet tall and fits perfectly in the bed of a small pickup. Let me know if you want me to take a picture of it and post it online.
Also, here's a link to make IDPA targets from grocery bags: