If it is not a straight in approach you would descend to your circling minima; typically 800 - 1000 AGL and level off to then visually manoeuvre (circle) to land on the active runway, keeping visual at all times and staying within the circling area for your category of aircraft. You would not descend to a 350' minima at right angles to a runway. If you get down to your circling minima and can't see the runway (or lose sight of it whilst circling) then you go around following the missed approach procedure for the instrument approach you flew, which can get quite complicated and needs careful consideration before you fly the approach.
PP