Arrange 2x4s in a sawhorse configuration. (/\----/\ ) 1 board across the top, 2 down on each end. Stable. Run fishing line over the top, through paper targets (or any other you can attach string to, to hold them down off the top board. You need a saw, hammer, more wood, and nails to repair pieces as needed...
PVC pipe (plumbing supply store) can be arranged in a similar fashion. But 1 down tube with T connecter and pieces on the ground for stability( J_----J_ ). Easier to break down before/after shooting. More brittle though, so wont hold up to as many direct hits.
One important consideration when building is to keep the targets away from the stand - so you dont have to rebuild it so much.
My friends and I made some target stands last time we went out shooting... we made it out of wood and steel hinges... the hinges were leftover steel beams from a construction site that were cut up into smaller pieces, probably like 10" x 10" with a hinge overhang so we could attach it to the wood.
ANYWAY, we brought a bunch of rifles... including some 5.56 rifles, as well as an L1-A1, and an M1A (308)... The steel was about a half inch thick, so we didnt think the rounds would penetrate.
When we were done shooting and wanted to disassemble our rig, we decided to shoot the steel plate with the AR-15 using AP rounds that were supposed to be "the shit". So we shoot it with a single round from about 50 yards, we here the "PING" of the metal, and know we hit it... so we walk down range to see what happened to the steel... Armor piercing my ASS! Made a little dent into the steel just a little bigger than the standard 5.56 rounds.
So we bust out the M1A and fire a single shot at the metal... walk up range and look to see what it did with a standard FMJ round... went through that steel like hot butter! Frigging AMAZING! I couldn't believe how much more punch the .308 round had over the AP 5.56! It was uncanny.
Needless to say, we used the L1-A1 and the M1-A to destory the target as the 5.56 rounds wouldn't do the job.
I got a piece of 7.62x54R jacketing stuck in my arm thanks to someones home made steel target spinner. I wont use them again as that sucked digging that out and it left a decent scar. Shoot N See for me, or I will buy a well made commercial steel target.
I shoot at alot of steel. Quality steel is a must. If it has any craters then you are going to get hit by splashback. The problem is alot of people try to shoot steel with rifle rounds close in. AR500 steel is only rated for rifle at 100 yard otherwise you beat the hell out of it and can't use it close in for pistol.