As dorky as you might think they are, I highly recommend a cycling bib (shorts with attached suspender type things that go under your shirt). I like knowing that my back end isn’t sticking out when I’m bent over really far and since there is no waist band, sitting in one position for a while means they won’t cut into you.
Personally I also prefer riding with the spandex stuff, ONLY because my shorts always seem to get caught on my saddle as I shift positions.