We recently tried a few items while playing a card game. One of the cards specifies household items. I liked the feeling of wooden spoon which is just the right size of spanking on hands. My skirt belt was not great and feels too flimsy for spanking.
What items have you experiemented with?
We’ve used big plastic spatulas - they’re broad and light and give a rewarding slap, but generally there’s a lot of give to them and not actually that painful.
We also had a set of bamboo utensils, so not just spoons but longer, broad, flat implements for stirring sautees and such - also fun as they had a stiffness, but still lightweight and relatively low pain.
Hear me out with this… a roll of cling film. Stings like a bitch.
I once slapped myself with a metal ruler 
- yikes!! Is all I can say
We have a set of long knitting needles. We use them like a cane.
Recently started to spank my husband with the back of the hairbrush- he loves it and secondly it’s do easy to hold (and repeatedly spank him) - other than that I have used kitchen wooden spoon and a large dildo ( makes a funny noise) 
I actually have a toy that is the inner tube from a roll of cling film with several layers of shrink wrap applied to give it some rigidity. It’s pretty damn evil.
But back to the original question,
Obviously you need to be careful using things that aren’t designed for it for impact as they can break and no-one wants cuts or splinters. But
Silicone kitchen utensils (avoid hard plastic ones)
Wooden kitchen utensils (be aware cheaper/older ones aren’t coated so you aren’t going to want to cook with them after)
Metal utensils (be super careful with these though)
Rolling pins
Rulers
Belts (go thicker or heavier, and/or double over)
Large hair brushes (avoid cheap ones in case the handle snaps)
Shoes (plimsolls and flip flops work well)
Tea towels
Fly swats (avoid super cheap ones)
Fish slice, whipped with a t towel,
Plastic fish slice, leaves a nice pattern on a nicely red bottom. Red area with white lines.
Super sexy.
We have used a plastic spatula, but normally our hands