My biggest problem has always been forgetting things when I leave the house. I was _constantly_ leaving for work, only to turn around because my wife called and said "you forgot your badge, you forgot your wallet", etc.
What changed this was a trick I learned from working IT in a large manufacturing company. We got to walk the line and learn from our customers, and one thing they had at critical stations were poka-yoke(0) trays. Think a molded plastic tray filled with exactly all of the things the operator needed to do their assembly, the bolts and nuts and fixtures and what not. So if you were attaching a pulley to a shaft you had a spot that held one pulley, one for a set screw, etc., and the spot was designed for only the right size screw so if it too long or too short you knew you had a problem. On each assembly the operator knew if their tray wasn't full when they started assembling or if it had extra parts in it there was a problem, and when they ended assembly if the tray wasn't empty something wasn't done properly.
One day I had the epiphany that this might just work for me, so I decided to make my own: I bought some craft foam and a plastic tray, and traced/cut spots in the foam for everything I needed for work – my keys, badge, watch, etc. Then every day when I came home my work things went into the poka-yoke, and I forced myself to not leave the entryway until it was completely full ... so no more "oh guess my wallet is in the car", I had to go get it and put it in. Every morning when I was leaving for work I'd empty it. My mornings went from ten+ minutes of me cursing and searching for my keys to... nothing.
In manufacturing this is often referred to as "Kaizen" [1], more specifically as 5S / "Seiton" part. There's even quite a substantial (though not cheap) market for kaizen specific foam inserts / foam sheets. Mainly these are easier to cut and have contrasting color for top and middle layers, showing obviously if a tool is missing from its place. Look up "kaizen foam" if interrested.
What changed this was a trick I learned from working IT in a large manufacturing company. We got to walk the line and learn from our customers, and one thing they had at critical stations were poka-yoke(0) trays. Think a molded plastic tray filled with exactly all of the things the operator needed to do their assembly, the bolts and nuts and fixtures and what not. So if you were attaching a pulley to a shaft you had a spot that held one pulley, one for a set screw, etc., and the spot was designed for only the right size screw so if it too long or too short you knew you had a problem. On each assembly the operator knew if their tray wasn't full when they started assembling or if it had extra parts in it there was a problem, and when they ended assembly if the tray wasn't empty something wasn't done properly.
One day I had the epiphany that this might just work for me, so I decided to make my own: I bought some craft foam and a plastic tray, and traced/cut spots in the foam for everything I needed for work – my keys, badge, watch, etc. Then every day when I came home my work things went into the poka-yoke, and I forced myself to not leave the entryway until it was completely full ... so no more "oh guess my wallet is in the car", I had to go get it and put it in. Every morning when I was leaving for work I'd empty it. My mornings went from ten+ minutes of me cursing and searching for my keys to... nothing.
(0): https://en.wikipedia.org/wiki/Poka-yoke