The shortest route to a long-lived tool is to treat the wear parts as consumables. Brushes, bearings, blades, belts and filters are designed to be replaced; the motor, gearbox and housing are not. Almost every tool that gets retired with a dead motor was running for months on a worn brush or a blocked filter that should have been swapped weeks earlier.
The first habit is to listen. A drill that whines, a sander that vibrates harder than it did last month, or a vacuum that runs hot and quiet are all telling you something. The second is to clean. Dust is the single biggest enemy of any motor, because it gets drawn through the vents and packs around the brushes and bearings. A minute of compressed air through the vents after every dusty job adds noticeable time to the life of the tool.
The third is to replace consumables on schedule rather than at failure. Carbon brushes are the cheapest single part to keep in the case — a fresh pair on a drill or grinder takes fifteen minutes and prevents the commutator damage that follows from running them to the stub. Sander backing pads harden and start leaving marks after a few hundred runs; replacement is cheap and immediate. Vacuum bags and filters lose suction long before the motor does — nine times out of ten a vacuum that has “died” simply needs a clean filter.
The fourth is to use the right consumable for the job. A TCT blade on metal will go blunt in a single cut; a wood blade on aluminium will throw chips. The cutting tools and drill and screwdriver bits ranges are split by material for exactly this reason. Impact-rated bits in an impact driver, cobalt drills in stainless, masonry bits in masonry — every mismatch shortens the life of the tool, not just the bit.
Finally, store dry and store charged. Lithium batteries hate being run completely flat and stored that way over winter; tools left damp in a garage rust at the spindle and bearings before they fail anywhere else. For a category-by-category overview of which wear parts to keep on the shelf, see the tool parts hub.