Cut some shapes of clothes - shirts, pants, socks, underwear, you get it.
I used felt so that I could use these pieces in future flannelboard activities.
Ask them to pin all the pants on one line, the shirts on another, and so on.
Ask them to pin all the brown clothes together.
Ask them to count the socks in pairs (2, 4, 6, 8, etc.)
Ask them to pin the clothes in a pattern (shirt, pants, socks, shirt, pants, socks, and so on...)
Then, have them make outfits with matching colors or mix-matching colors by laying out the clothes on the ground.
The clothespins can be dangerous, but they are great for working on hand and finger strength.