Seconding Ryuichi on binders. Underworks work better for some guys (they're made with a very firm binding material), but in my experience you breathe/move easier in gc2b. I've tried like five different brands, and for me it gives the best compression/shaping without strangling me. Results differ depending on chest/rib difference--I have a medium-sized chest, and need a firm front panel but plenty of back stretch for comfort. If you are really exerting yourself, consider wearing a size up or a slightly stretched out binder--and make sure that in general you go with the size that fits you. Too-small binders don't really give you much in terms of visual gains, they just cut into your skin/compress your rib cage/make it hard to breathe/potentially do tissue damage that may affect top surgery results if you choose to have top surgery later. Find the happiest medium you can between appearance and comfort.
Whatever you choose, please don't use ace bandages--you can break ribs.