I wear the bonds feeding singlets, they are fantastic. Though they generally flash more than what most want to show but just tuck the spew nappy (i.e. flat nappy lol!) under the strap and there you go, no peek-a-boos! bit exy, about $25-30, but if you can grab them on sale they are great.

Kmart had a breastfeeding singlet a lot like it though when you unclipped you would still be covered, and there was a little slot to poke the nipple through. I liked those because you aren't exposed quite as much but the support isn't the same and my straps kept unclipping as they aren't very secure.

At home if I'm just wearing normal clothes I just pull my shirt up, which is ok but bares my stretchmarky jellybelly lol, not something I'm willing to do while out, but if you wear a singlet underneath (easier in winter than in summer though) that solves that problem.