Outdoor housing is pretty limited to just having basic outdoor amenities. You can't be too creative because you don't have enough furniture slots to combine to make something elaborate and you don't have enough land area to use before things start looking cluttered. For my cottage, I can place a mailbox, mini-aethryte, garden plot, chocobo stable, lawn bench, table and a tree or two.
If I feel creative, I just use my island's 90 slots. There are some wonderful things you could do but sadly you can't really share your creations there. Here's the garden I've been working on (shameless self promotion).
https://imgur.com/a/zxOQm07