I learned this about a year ago, and found it really helpful.
Basically, it goes like this. You only touch work one time.
That means if you pick up a box in your car that needs to go to the bedroom. It doesn’t first go to the kitchen table to sit for a while, rather it goes straight to the bedroom.
It means that if you open a bill, it gets paid immediately, which further means, you don’t open your bills until you are ready to pay them.
The benefits of this rule are great. Besides the fact that it results in less physical work, I find that the most amazing gain is mental. Specifically, I am not always passing the box in the kitchen thinking, I really need to take that upstairs. Or fingering the bill that needs to get paid. You get the idea.
Apply the touch once rule.