Product design

How much should I charge for product design including hats, shirts, polos and sweatpants etc?
Someone asked me and not sure how to charge as I’ve nver done this before for a client.
Thanks

Is this just for placing a logo on a mockup kind of thing?

I think its more to actually make a design on the clothes as well as a logo
Not just as a mockup but for print/producing it as well

You can tell your client you haven’t done this type of job before so would prefer to work per hr but after 1 part of the job you can reassess and try to make a job per item to design. You can also aks your client to suggest a fee.

OK thanks for the advice