Yes to nursing vests under bigger tops. At first I thought "breastfeeding friendly" meant lots of shirts, cardigans, etc. Wrong... these garments still leave you totally exposed! Took me weeks to figure it out. Slightly loose (but not too loose or it'll get in the way) is good for the over-the-top layer.
Having said that, long cardigans are useful - ones with pockets. I only ever look for things with pockets these days, you won't have the freedom to run about looking for your phone etc when you have a little one (or even a toddler) on your hands, so keep an eye out for pockets!
On the "hands-free" front, look for shoes you can slip on without having to crouch down to do up laces, straps etc. You want to be able to shove your feet in them and get out the door in one smooth movement. Crouching down with a baby strapped to your chest (or with stitches in your perineum, for that matter) is no fun.
As for bottom halves - I am still living in leggings and other stretch garments. So much easier.
Think of your outfits as a uniform. You want to be able to reach for an outfit without thinking too much about it. So I buy a lot of things in black, grey marle, grey etc just so I don't look too pyjama-ish. It sounds a bit boring but I know it looks more chic than if I were getting about in cheap & cheerful-looking colourful prints that don't go together.