What type of sanding / finishing sequence have yielded success for you when building face frames for cabinets? Do you sand and finish prior to assembly? Sand only before assembly and finish after? Sand and finish after?

Sand before assembly and finish after seems most intuitive but I am doing it for the first time so I thought I would seek the advise of the experts. How about the back of the frames - do you follow the same finishing schedule without sanding?

Thanks in advance for your time . . .

Larry