I used to use sardines, canned jack mackeral, or cut up blue gill. However, the cheapest and most effective bait that you can use is dried dog food. The coons love it and they are used to human scent being associated with it because they are always going up to peoples houses, barns, and dog pens to steal it. A five pound bag of the cheapest dog food you can find is only gonna cost a couple bucks and will be enough for an entire season or beyond that unless you run a heck of a lot of traps.