Tree slices--there are actually so many options now as these are popular in the wedding and craft circuit. One entry even looked like it understands loose parts play!
Wooden Acorns--we love these and have purchased these a few times! People often stain or paint these as well. You can even find acorn caps!
Peg Dolls--These can be decorated in many ways or left plain. There is also a "winter variation"!
Wooden Circles--Another item I have purchased many times! You can also just get lots of different shapes.
Wooden Letters---These can be another way to incorporate literacy. Use in sensory bins, in a basket, or in free play.
Sticks--I seriously never thought I would buy sticks, but when I found some at a local craft shop while working on Fall Loose Parts Kits, they were really handy to have semi uniform sticks that required absolutely no effort on my part!
Wooden Leaves and shapes--I got these for a fall swap as well, but there are options for many holidays and seasons.
Wool Balls--I have really loved these wool balls. There is an assortment of colors and sizes. I could not imagine making all of these and such a different quality from pom-poms. Pair with acorn caps for precious colorful acorns! You can find them with specific colors, too.
Felt Spirals and Flowers-- I found some of these at a yard sale and love using them. I have also cut out leaves from felted wool--it helps me appreciate "clicking" them into my cart so easily!
Divided Containers--I watch for these at thrift stores, but found this online. The squares are small, but look like they would work well!
These contain affiliate links--thanks for supporting the site with no extra cost to you! I'm sure there are more--these are a few things I pulled together tonight that I use more regularly.