This is an ongoing issue for me.
Where the strap meets the top of the cup on the shoulder, I find that the seam between the cup and the strap often rubs and actually makes my skin really red and sore. I think this is partly because I have narrow shoulders and the straps possibly sit further away from the centre of my bust. But I now have several bras- all different styles but mainly push-up underwired half cups - which fit really well except for this rubbing.
The annoying thing is that it's only noticeable after half a day or so.
any ideas?