I don’t remember the exact episode but it was one of the last few.
I’ve ceramic sealed a few vehicles and four bikes now, so have a fair bit of experience. It’s pretty straight forward and definitely easiest to do when the bike is new and in perfect condition.
My recommendation is to do a ceramic spray. This is super easy to apply and hard to screw up.
A kit like this would get the job done:
You want to prep the frame. You want to get it really, really clean. Then you want to spray with isopropyl alcohol and wipe with a clean microfiber. This gets off any remaining residue and grease. You then apply the ceramic sealant (per the manufacturer instructions). You let it dry/flash, then polish it with a microfiber. You then want to leave it overnight to cure. The next day you can apply a “boost” product like this:
The boost will add to the shine and can be reapplied periodically.
Between rides I usually clean my bike with waterless wash: Adam's Polishes Waterless Wash & Towel | Waterless Car Wash
The waterless wash has a lot of lubricants in it and helps prevent scratching of the frame as you clean it.
If the bike is very dirty, then I’ll soak it with a foam cannon and MegaFoam soap and then wash with a microfiber, before rinsing with a low pressure sprayer.