I think many good ideas have been mentioned. One that hasn't been covered is the time it takes to overcome our procrastination to accomplish a shop project that's beneficial to everything that happens in our shops. It could be anything from painting a wall (white preferred) to installing an electrical outlet or a light. The paint and light helps with the vision and the outlet helps with the time saved stringing an electrical cord, along with the safety factor (trip/fall) involved. My experience has always been; Why did I wait so long!
My shop is for my business but even with 3.500 sq. ft. I still deal with the 10# in a 5# bag syndrome (addiction) to acquiring metal working equipment, along with not sell something I no longer use. With the exception of my old Lodge and Shipley lathe and 1980's Bridgeport mill, the remainder of my shop equipment is sheetmetal/welding fabrication related, but this still requires isolating grinding (abrasive) projects from shears, brakes, and anything that has a way or gib coated with lubricant.
Even when I do the shop layout to scale prior to moving in, I still encounter space issues or find myself walking around something which adds too many footsteps to the process. A few pieces of equipment require a forklift bigger than my 5,000# lift so I try to position things one time. Losing 200 sq. ft. (more than most hobbists work space) on my last move has been a struggle. After moving my sheet storage rack about a year ago, I discover I need to turn my shear 90° from it's current position. It's only been about two months since this epiphany so hopefully I will get this done soon. I'm hoping a pivot on one anchor bolt will prevent running new electrical.