And then tracking that, so if one group of contractors has consistent problems, they can be fired.
(e.g. the walls in my (rented) apartment are mostly really solid. Some parts won't even yield to my hammer-drill. Putting up my projector was easy (hollow wall) but I spent 2+ hours putting up my projector screen on the opposite wall (even though only 2 screws).
The hard part is to measure and plan appropriately (they offer an online 3D tool as well as free in-store consulting here with 3D modeling), but the assembly of the pieces is a cakewalk. I say that as someone who's literally in the middle of some IKEA kitchen assembly right now.
IKEA's kitchen modules are also brilliant for non-kitchen applications. They work for any kind of storage. Skip the fronts (limited selection, cheap-looking), countertops (mostly fiberboard) and handles, and use the modules as "hulls" dressed with better materials. Third-party vendors include:
Superfront — https://superfront.com/
Semihandmade – https://www.semihandmadedoors.com/
Kokeena – http://kokeena.com/
Dunsmuir – https://www.dcabinets.com/
Reform – https://www.reformcph.com/