I wear a cock ring all day except for while showering, pumping, lifting and man-scaping. I wear one that is snug (not too tight. Your penis should never turn blue and you should be able to pee without hindrance . I bought a set of three rubber cock rings and wear the largest one around my whole package, behind the scrotum) enough to keep me more engorged than usual.
Sometimes I use an adjustable ring right after pumping to get my penis extra turgid for a small edging session. You want to always keep your penis engorged/elongated after PE to promote healing in that state otherwise you simply won't gain.