Too often people try to Detail under fluorescent light, which is good for general illumination and for evaluating texture (i.e., orangepeel) but totally wrong for other types of paint inspection. Point Source Illumination is almost always best, and doing it in an otherwise dark environment is often pretty much mandatory.
A Ceramic Coating applied over marred-up paint would be pretty bad looking, so having the Inspection Lighting right during the correction (and being able to do that correction, remember that on these cars you shouldn't take off more than ~16 microns of clear over the life of the oe paint) will be just as crucial as having it right when doing the coating.
So will be stripping any Polishing Oils left by the compounds/polishes, easier said than done with some products. Don't expect dish soap or rubbing alcohol to suffice.
There are apparently some *self-healing* coatings out now, but AFAIK, they're only available to certain Detailers who have the right certification.