Just started working on my first custom worldspace. Was wondering if there are some specific things i should watch out for or things you wish you knew before creating your first worldspace?

Generate LOD, especially terrain meshes, as often as possible (within reason), especially after making large changes to your worldspace. With Fo3, this wasn't possible, so I had to assume my worldspace looked good as a whole (luckily it turned out well). However, in Skyrim, you can regenerate land meshes in around 20 minutes with a decent CPU. Use this as a tool to gauge the realism of your worldspace. It's hard to tell if a mountain looks unrealistically steep or if the land is too flat without regenerating LOD every now and then.