I think that it depends on the asthetic you are going for but basically I would say that it is easier to have some type of guide (whether it is numbers or alphabet letters).
If you don't want to go with the typical "Chapter 12: Bla Bla Bla" or "Ch 12: Bla Bla Bla" then you have several options.
If your story will be divided into archs you could write something like this:
- Part 1 - Chapter X: XXX
- Arc 1 - Chapter X: XXX
- Volume 1 - Chapter X: XXX
- Arc [Flower Garden] : Chapter X - XXX
Or something along these lines.
If you are not going to split your story into volumes/arcs or whatever you want to call it then these are the options you have:
- XXX
- Chapter 1: XXX
- Ch 1: XXX
- Chapter A: XXX
- Chapter A (Part 1): XXX
- Chapter A.1: XX
And since I just woke up this is as far as my memories reach. Hopefully I was able to help you
(forgive me for any mistakes, I am writting on my phone)