I typically haul as much as I can fit in the backpack plus the camera. So a full complement for me now is:
K-3ii with the SMC A 50/1.2 and battery grip (Start with this)
Sigma 300mm f/4 APO Macro
S-M-C 200/4 Takumar
Vivitar Series 1 135/2.3
D FA 100/2.8 WR Macro
DA 77mm ltd
DA 35/2.4
S-M-C 28/3.5 Takumar
S-M-C 17/4 fisheye Takumar
A smaller travel tripod with a manfrotto 3047 head on it
A 77mm CPL and set of step up rings
A Vivitar 285HV flash and spare set of batteries
M42 adapter ring
Reverse mount ring
M42 extension tube set
M42 helicoid
A spare set of batteries
A spare set of memory cards
I basically take that with me when I go out unless I know I am doing a specific type of shooting like astro and then I take multiple cameras with specific lenses on them for each of my tripods. Even on a long hike I will haul the full bag around like I did last fall with the boy scouts up at
Jay Cooke State Park as we did a 15 mile hike on the "technical" trails. Got a nice grand tour of the park and for most of the day we didn't run into other people