At present I have one real camera bag from my film SLR days, a Lowepro Street and Field 200 I believe. It is much too large for a Leica and a few lenses, and while large enough, doesn't have enough pockets for two Leicas and a bunch of lenses. My other bag isn't a camera bag at all, but a small Bally messenger bag with no padding that is perfect for a Leica with lens attached, another lens in a soft pouch, a spare batter, a filter or three and perhaps a sunglass case, all without looking like a camera bag.
For gear I am not Leica and iPhone only, having sold my last DSLR and Sony NEX. Here is what I typically carry.
Walking around: No bag at all, either the M8.2 with the 35/2.5 Summarit or the Monochrom with the Zeiss 50 Planar. No hood as these are extremely flare resistant and I want to keep things small.
Regular work day: The Bally bag with the Leica Monochrom and either the 35/2.5 Summarit or one of my 50s (Leitz 50/2 Summitar, Zeiss 50/2 Planar, Jupiter 3). Sometimes I will switch the 50 for the 75 Summarit.
Weekend trip: Bally bag with the Monochrom and Leica 28 /2.8 Elmarit Asph, 50 (usually the Jupiter 3) and Leica 90mm Summarit
Photoshoot or overseas vacation: The big bag with both the Leica Monochrom with the Planar 50 attached and the M8.2 with the 28/2.8 attached. In the bag are the Planer, the 35 Summarit, charger, 2 extra batteries, 2 extra SD cards, plug adapter (depending on country) and an assortment of filters, lens hoods and lens cleaning products.
The biggest downside to my current outfit is all of the different filter sizes. If I'm just taking the Planar (43mm) I have and will use 43mm filters on it, but when carrying more than one lens I'll use a step up ring on my 50mm (39-46 for the Summitar, 40.5-46 on the Jupiter 3 and 43 to 46 on the Planar) and limit myself to a 39mm and 46mm IR/CUT for the M8.2 and take either yellow and red or settle on only orange for the Monochrom.
Then of course there is the mini tripod (an old collapsable Polaroid), cable release and some extra money hidden in a bag pocket.