I’m not really what you’d call ‘green fingered’, but I do try with my veggie garden and my house plants (and I think that in this instance practice does make perfect).
I’ve long had a soft spot for terrariums and their mini landscapes.  They are so beautiful and intricate, and meet all my requirements of both form and function 😉
I stumbled across Angles & Earth the other day, and their terrariums are pretty mesmerising in their exquisiteness.   They’re based in Cape Town, and you can buy online, or take a terrarium class, which sounds dreamy.