I currently have two daily use bags - a messenger bag/satchel type - it takes my ipad, make up and first aid type stuff, purse, keys, phone, torch, knife and bright pink case that houses an odd-looking funnel-and-tube contraption - it makes splashback in some situations less problematic
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The other is a small rucksack which I carry if I know I'm going to bringing stuff home with me. Or my shoulder's playing up. Or I'm going walking for a day.