Like many women who have spent most of their life with smaller breasts (until after sprog 2) I didn't bother with them once I had got through the 'padded bra because all the other girls have curves and I don't' stage of life. I am always aware of wearing one when I do so I suppose I am unused to them really.
When I do wear one for 'best' I have 3 fitted M&S ones that are not too uncomfortable to wear and do give a decent shape to the outline, as it were. For other times when out and about and feeling I need to conform I tend to slip overs or sports type bras.
For washing, mine go in with the light colours after one or two wear days but they are not full days because, once at home, the bloody bra is the first thing off!