There are a few different types of stabilizers that can be used for tea towels, and the best one to use will depend on the type of fabric you are using and the look you are going for.
If you want your tea towel to have a more vintage look, then using an embroidery hoop or frame would be the best option. This will help to keep your fabric tight and prevent it from sagging or wrinkling over time.
If you are using a thinner fabric, then using fusible interfacing would be a better option. This will give your tea towel some structure and help it to hold its shape better. Just be sure to follow the manufacturer's instructions when applying it.
And finally, if you are looking for something that will really hold everything in place, then using adhesive spray would be your best bet. Just keep in mind that this may make your tea towel less flexible, so it's not ideal for every project.