Very artistic-looking pictures; I like them quite a bit!
Question: do you have any experience with IR photography? I'd heard of it before and thought it was just a way to get quicker focus locks in the dark (by using an IR light), but apparently it's a whole type of photography in itself. By using an IR filter you can see some really interesting things... since you're a fan of monotone photography, I thought IR might be something you'd be into, as well. IR isn't quite monotone but it often comes close. When there are colors they seem a bit faded. It results in overall ethereal pictures.
I haven't checked the prices of IR filters because I'm afraid that they're going to be really pricey
But if they're not too bad ($20 or less, I hope!) I'd definitely get one. Check out the "False Colors" section of
this website for some examples of IR photography. The last one shows how colors come out, I think... perhaps he manipulated the image.