Poly fill for me.

I use poly fill, But I use quilt batting, you buy it at craft stores. I buy a yard at a time, it's like 4 feet wide. I lay a straight edge on it and sharpy lines about 2x2. cut it into squares its 3/4 " thick works great. I can use it on about every size trap, it's cheap, only draw back I see is a coon or coyote will destroy them, but hey at a couple cents apiece who cares.

wws

Usually peat or nothing. In good soil, you don't really need pan covers, or plugs. In sand, different story.

Polyfill here for so long now I dont ever remember using anything else.

Neither

Pan covers are a joke where coons and wise-guy coyotes are concerned.

Poly works much better, but it's just a bit too time consuming for me.

I'd been using DIY foam pads for quite a few years before I posted it up on T-Man.


DIY PAN PADS

Nothing
I trap mostly frozen ground so I have a system that works for me
Salt is my friend

Like polyfill, but it does cost me cats and coyotes over wire screen. Polyfill is sure fast and easy though. Use it still on #2 duke round jaws and smaller traps.

I use coffee filters.
I did use poly fill until I got a batch that was contaminated with some foreign smells.. ( not my doing) and my sets kept getting dug out..took a little bit of detective work to find out what in hades was going on.
I’ve never had issues YET from coffee filters.
I know some folks like cupcake papers.

I trap mostly in pure sand. Wind driven sand migrates into the poly fill and the trap won't fire I now use coffee filters. I like the big brown ones.

Big traps that might soak a while, steel screen.
Sometimes natural under or over,
sometimes nothing.
I've had my fill of poly.

Everyone should trap
freeze thaw rain freeze snow,
at least one season.