It’s a perennial problem for modellers - what to do with those kits and collectibles once they are bought and built. For me the biggest issue has always been dust and delicacy. The problem goes all the way back to childhood, with my dear old Mum’s well-meant attempts at "just dusting" my room, with the inevitable consequences to delicate parts such as aerials, pitot tubes and the like.
Later on it was girlfriends - my flatmate Keith once opened the front door to say, “She’s hiding and daren’t speak to you... you know that Ford GT40 you built... she was only trying to help”. You can guess the rest! Suffice to say, a glass of wine and ‘personal attention’ earned forgiveness without too much trouble.
These days, I try and use dedicated shelves and display boxes wherever possible and, importantly, pack most of the collection carefully away like a museum, with only a selection on show at any one time. This approach can work, provided there's enough garage (or loft) space to keep the resting items dry and safe. But do keep these in sealed, stackable plastic storage boxes, with a sachet or two of silica gel inside each box to protect those treasures from damp, especially if you keep the cardboard boxes.
For your ‘on-show’ displays, there’s no need to go to huge expense. Wine and port presentation boxes can be reused after Christmas duty (top picture), shown here painted white, and fixed above a doorframe to utilise every morsel of wall space. Acrylic Ferrero Rocher chocolate boxes (middle) are terrific for small items. They come in different shapes, here a transparent pyramid. I’ve even used ultra-cheap teen girls’ makeup boxes from a thrift store (bottom).
What all of these solutions have in common is that they keep out the dirt and dust!