Therapy for flat feet.

Are there any exercises that I can do to develop healthier arches?
I have had orthotics in the past and they have never really felt comfortable to wear for long periods of time.
My feet don’t bother me when I am barefoot or wearing loose sandals, but when I am wearing lace up shoes and especially dress shoes they become painful.
It feels as though the muscles in my feet aren’t strong enough to hold their shape in rigid shoes where as in loose shoes my feet can slid around.
Is there anything I can do to strengthen my feet so that dress shoes aren’t so painful