Have three, ‘bags’ on the bike.
The, small, ‘Headlight’ bag. The Insurance Card, a small, screwdriver, with various bits, a crescent, a few wrenches, hand warmers, set of gloves.
In a rear side bag, a, ‘Rain Suit’ (Frog Tog Knock Offs) Head Gator, another pair of gloves. and a few more tools.
All those items are permanent.
Most of the rest of the room is empty, to accommodate, a trip to the hardware store, for, ’things’. or the ‘mail’, or, the Most Important Thing, “Amber Fluid”.
Other items, which I would think I would need, are in, ‘packets’, then they go in, if I think I may need them. And what are in those, ‘packets’, of, ’things’, are all dependent on where you go, how long you ride, and where you live.
Their is one member here, who rides from, 200 feet to 5,000 feet, and, “scores Nice Leather Jackets”.
Which, Of Course being in AZ, “Does Not Need”, and is Totally un willing to, ’share’.

Anyway, a suggestion is: Pack/Have, what you think you will need, ‘ALL the time’.
Than, ‘have’ things ready to pack, for, "That Trip”.