I always build my models with transportation in mind, as I cycle or skate to games.
For my DEldar this meant avoiding a LOT of spiky bits!
My Raiders and Venoms have removable flight bases, no underside fins, and the rudder carved to not stick below the belly. This means four of them can sit in half a KR case.
No masts, aerials etc. No hull spikes. With a bit of felt laid over them, that's half the height of a KR case. I have almost 1,500pts in a single KR case!
I use a Raider as a Ravager: if you buy two Raiders, you get two single gangplanks, so I built one as a Raider with no plank, the other with both planks, and added a magnet to each plank. With a pair of magnetised Dark Lance Kabalites standing on the planks, you have a perfectly good Ravager.
This edition I am not using Ravagers, so it means I have four Raiders ready to go!
Also, Magnetise your characters and sergeants, and have magnets on the deck of your boats. I can put an Archon, a Sybarite and a Blaster in my Raider, and position it on a sloping bit of terrain, without toppling. It helps you and your opponent so much in-game if you can both see what units are riding in it!