I have to say that I prefer to 'pull down' than 'pull up'. Here is my reasoning: Pulling down means my belly isn't exposed to eyes or cold and I don't have to bother with two layers, especially in hot weather. Pulling down is quicker and means an instant breastfeed when using my Ergo (which means people won't even notice what I"m doing because DD hasn't cried because the boob has reached her mouth in lightning speed!), or even any of my slings for that matter (no pulling fabric out of the waist strap). Pulling down does show the TOP of my boob, but the rest is covered by DD from view and I can tuck it all away into my bra straight away before DD has to pull away. There, that's my tip for quick, fuss-free and 'modest' BFing in public
I am a practical person and generally I make choices to make my life easier and more efficient than for other considerations (though it's great when practical coincides with my aesthetic preferences!). Cross-over tops and dresses are just the bees knees for BFing, home or public. As are stretchy V-necks. I have a wrap cardigan that I got for sling-wearing warmth - it's a long rectangle shape of lovely Italian wool with lurex through it (bit glam) that has sleeves attached to holes for arms and the 'flaps' of the rectangle cross over the baby bump (baby in utero or in a sling, it's a great preggy item) for warmth, and can be used to loosely drape over the baby when feeding to obscure 'side view'. My favourite boutique is in my little town and they know me - I go in and pull down their garments for breastfeeding-friendliness! It's gotta be easy to feed in (cos I'm still feeding my 3.5 yo my gear has to be good for the long-term) or I'm just not interested.
Hey, whaddya know...back on original topic