+1 on the comments about small items and the tool kit. I've just switched from winter mode (solo, long range, lots of rubbish like snow chains and a *****y great sleeping bag) to summer mode (two adults plus dog, neat clothes for restaurants, intercom etc.). In the process I've used the tool kit to give the bike a decent service, fix salt damage and so forth. I noticed the tool bag was now a struggle to close so went back to the list. Almost 5 KG of extra bits like allen bits and single size spanners had sneaked in there just because I'd thrown the odd bit from the garage kit in the bag as I'd moved about the bike.
Stick to the details and the weight will come off.