This is a quickie, but useful.
When making a load screen mesh, testing it is normally a pain in the ass. Who wants to have to repeatedly fast travel for however long it takes before it shows up, only to get a fleeting glance at it when it does?
The solution is relatively simple, and maybe slightly clever, who knows. Simply make a copy of the mesh in meshes\interface\logo\ and once it's in there, rename the actual file to logo.nif.
Then all you need to do is load the game. Your mesh will be on the initial menu as the background image. You won't get the benefit of the camera path behavior this way, or be able to spin it like a real load screen, but you can at least use it to adjust the size and rotation of your mesh in Nifskope until you get it where you want it.
The changes to orientation need to be made on the very top node, which is likely a BSFadeNode node. The translation, rotation, and scale values should be adjusted. You then have to right click on the top node and select "Transform -> Apply" before the changes will be detected by the game.