For longer rides I use a wingnut pack, feels like you’ve left everything behind until you need it, far better in my opinion than a conventional pack. On shorter rides bottles on the bike and tools in a seatpack. And you can get bottles with covers to save drinking sheep poo.
I use a bum bag for short rides. Much more comfy than the backpak
Phone, tube, small pump anda waterbottle all fit in and it more or less dissapears if wearing a jacket.
Not used a Camelbak in over a year, just don’t really like it. Bottle on bike, if it’s hot I’ll stick another one in my back pocket, which is more liquid than my Camelbak holds anyway. Tube and CO2 pump in one pocket, multi tool/credit card/phone/keys in t’other.
Never had any issues with crashing onto stuff, reckon you’d have to be bloody unlucky, just as likely to hit hard stuff on the ground!
Tend to stop mid ride once or twice to top up on water and have a piece of cake anyway, if I was heading ‘into the wilderness’ as it were then I’d carry more crap.
I have done this recently. Below is a pic of what I usually carry.
1. Lezyne bag with multi-tool, pouch of bits and bobs inc a puncture kit, spoke key and powerlinks, crank tool and spare plastic bit for Shimano cranks, co2 canisters.
2. Inner tube, DHB jersey bin with phone, cash and card.
3. Waterproof bag with a waterproof jacket.
I usually also have an energy bar.
1 Bottle should be fine for a couple of hours.
I can also squeeze in a battery for a helmet light too.
Anything under 2 hours (excluding hot weather), it’s pump, tube, CO2 and multitool in the jersey pocket.
Over 2 hours I can make do with a saddle pouch and pockets but I’d have to refit a bottle cage for water. I can carry enough stuff on the road bike easily enough so the MTB wouldn’t be different. I can even shove a kindle in my pocket on one-way road rides for the train ride back (Sunday trains a bit infrequent in the sticks).