Straw or hay sets will work, I still chip out a trap bed(especially if you use bait,they will scratch) use rerod stake. Point the stake and use 14-16" of chain and a couple of swivels. A coyote can screw a rerod stake out if the chain gets wrapped. Standard flatset with buckwheat hulls and waxed dirt will work if temps stay below freezing. I only go to sodium chloride as a last resort, traps are bagged(sandwich) and treated with full metal jacket dip. Make sure any trap bed is just big enough for the trap to prevent movement of trap when the coyote scratches.