Heres a tip I learned a while back. You may notice when slewing or even just when flying that your scenery isnt fully loaded ie the cround textures are blurry or there arent as many trees and buildings as there should be. Microsoft hid a little key command from us that can solve this issue in literally a few seconds.
Under key commands in the options, look for a command called Refresh Scenery (I am 99% sure thats what its called, I dont have the sim running now so I cant check). This command does what it says, it refreshes scenery, reloading all objects and textures. I have it assigned to CTRL+SHIFT+R. Try it out yourself!