There is a huge amount of information in many of the books and internet sites written on the outdoors, about various sorts of traps, so I wont go into too much detail. However a few pictures and some of the problem areas discussed, can help folks get off to a good start. If you are not careful this subject can be frustrating, but teaches patience and that small details are important.
Figure four dead fall trap
Make sure where the upright and horizontal bait sticks cross, that there are straight sides to the notch on the bait stick so that it locates firmly. The longer notch on the upright, enables the sticks to travel when disturbed.
A longer and complete weight would be better than as used in the picture, to prevent gaps that don't crush the prey properly.
These are supposed to good for catching squirrels off the ground. They can cause a swift kill, hold the prey well, and raise off the ground away from other predators.
Make sure the pegs anchoring the rest bar in place are sufficiently knocked into the ground to resist the significant force exerted by the sapling, which needs to be strong to work properly.
Make sure the tensioning stick (the short one tied to the string after the noose) is on the outside of the rest bar, so that the noose pulls up and over it, going cleanly up into the air.Make sure the slip loop on the noose stays as a loop when loaded under tension, so that it tightens quickly.
Be careful to target the correct prey by observing the area beforehand and watching their feeding habits.
This fellow likes to graze on willow leaves ; )
Check traps a couple of times a day from a distance.