I will be selling them on a Facebook page, through word of mouth and occasionally at a flea market. Do I need any sort of tax id, employment id? What forms would I need to fill out?

All depends on your location..

I live in Georgia

If you sell them on eBay, and other others, outside the state of GA on the internet, there is no tax.

If you sell to anyone in the state of GA then you are to charge sales tax on the goods you sell. When reporting your tax, you can deduct the tax paid on the material to make these items. You can with a Tax ID number also buy your material with out tax.
You have to file your Tax ID report every month and there are high penalties if you don't.

Also normally if your "flea market" is going to be a on going businesss you are to have a business license ( depends on your exact location)

And just to make it sound even worst, remember if for example, a dye from one of the bows contained a material that hurt a person, perhaps caused hair loss, or the color faded into their hair. They can sue you for damages. So if you are making something, to protect yourself, product liability would be needed.

Not that anyone often has the insurance, just want you to know the risks.

Thanks a bunch Fr Chuck!