I'm looking for one roomy enough to take an A4 size pad, slim compact laptop (which I haven't bough yet either...) and an assortment of whatever else lives in my usual tote bag - phone, charger, small make up bag, bottle of water, coffee cup, sandwich, etc. So it has to be fairly practical.
If you have such a bag, what do you have? I don't know where to start looking. It's been ages since I've bought a backpack and feel like I'm back at high school!