Hi! I'm Marco (not really, see if you can guess where my name is from ). I'm 19 years old, and I first got into David Mitchell by reading The Bone Clocks. I've also read Ghostwritten and Cloud Atlas, but I don't care about spoilers for the other books so much, even though I'm definitely gonna read them. I also write a little bit myself (not anything very good yet though, but I hope I will!), so if I decide to write any Mitchell fanfiction, I'm definitely gonna post it here! Other than that, well, there's not so much. I enjoy reading in general. I like HP, but not as much as everyone else, it seems.
Hello Marco! I take it your username is referring to Marco, the narrator of Ghostwritten's London chapter?
I can highly recommend reading the other Mitchell novels. In my opinion, most of them are all the better for not having been spoiled, but like you, I first started out reading The Bone Clocks, so my reading order wasn't the 'intended' one, either, so even if spoilers aren't too important to you, the books will probably be quite enjoyable for you.
If you do write any fanfiction, I would be delighted to have you post it here! You can use the board Cavendish Publishing for that. Also, if you want to share some of your other writing, you can always post it on the Miscellaneous board.