- express the breast milk and use your storage if you plan to go out and you can feed using bottle
- look for baby care room if you are out in public, if there isn't any, I'd try to go to fitting rooms (in shopping malls) or just choose a bench with not so many ppl walking around and breastfeed by covering a napkin from your shoulder over to your baby
- surf Net, check whether the place(s) you are planning to go has a baby care room
I'm sure there are many other ways apart from those I can think of above (which I normally do anyway). I think the most important thing is to give your baby a chance for good things - your breast milk! It'd be very selfish to not breastfeed just because you are worried of how ppl would look at you!
Personally I find that it is very very womanly and it's a great gift to be able to breastfeed your baby. I totally supports breastfeeding!