If you'd like a smooth, matte finish, taking it up to 4000 grit using all the grades in between is a safe method (500, 1000, 2000, 4000).
If you'd like a polished finish, I'd suggest skipping the Rough Buff and then Polish sequence. It is complicated; they use machines at the factory and it's not easy to replicate.
May I suggest keeping it simple as possible?
Sand it first to maybe 1500 or 2000 grit; then use a mild, non-abrasive polish (e.g. Snake Oil) to put an initial light shine on it. Apply a heavier dose of polish for more length, as needed. If it is still not long enough, sand to 3000 or 4000 grit and start with light shine again; then apply more as needed or as desired.
The less things you do to a ball, the easier it is repeat what you did.