1L243, I am also a compulsive modder. It's fun! My stick house is a mess, but my trailer is up to date.
The most useful project I have done is to tear out the existing cabinetry to put in custom shelving. The stock cabinets were made of thick plywood and MDF, with poor allocation of shelf space. Also, there was a large vanity mirror as part of the setup -- useless.
So I built my own enclosed shelves of thin Baltic ply. Here is how I did it:
Scroll down to the shelvingAs a result, we now have more than enough room for our clothing, toiletries, boots, and so forth.