Well, since you asked.
Multimeter
Honda tool kit, plus 3/8 ratchet set (HD's ya know :cheeky1

and misc screws & nuts.
Battery jumpers, battery charger, tape, screwdrivers
Tire repair kit (plug, not patch)
Bike had a compressor, so had an extension hose
Gas filter, roll towels, big & little ones

Alcohol plus 1st aid kit plus lots of sterile gauze
GPS if needed, bike cover, 10x10 tarp,
piece of plywood for the kick stand
Fuses, all kinds. others might need them.
Crimpers plus various kinds of connectors.
A couple of coils of low voltage wire. 16 ga & 12 gauge
Couple of spare headlamp bulbs, spare tail & side light bulbs.
Most of that will fit into medium sized fanny pack.
The bike cover takes up the whole trunk because it is a Beverly Bay 3 layer UV proof. Well worth it to me, it has kept me and the bike dry during a horrible deluge.