Where are you herping? Your backyard, a tree line, brush area, forested area...? That'll make a difference as to what you bring in. Non-treated wood such as a sheet of plywood in an open area or near a "border" area (tree line to start of grassy area or edge of body of water to tree/brush line, etc.) is a good start. What are you looking to find? Anything in particular or whatever reptile/herp you happen to come across?

I built a snake "trap" in the windbreak of trees on my property. Put up silt fencing that construction companies use to keep the dirt from washing away as wings about 10' long in either direction from the apex point of the trap, which was a wooden box with hardware cloth for the bottom/sides and a solid wood top. I cut small holes with wooden ramps leading up to them in the sides of the box toward either wing and then just checked it daily.

The wings were staked to the ground and directed snakes into the trap by them trying to find a way past the cloth. Caught a few corns and one really grouchy copperhead in the two weeks I had it out. Passed the time in the summer growing up, lol!