for single target, you want to be able to fit two goring blades into your fight or flight duration. you do this by using fight or flight right before goring blade, do your standard royal authority combo twice, then goring blade once more, repeat.
later on after 60 you get requiescat, you use requiescat after the last goring blade to holy spirit spam as much as possible. confiteor and atonement are little additions to this you also get later on, being able to use atonement after royal authority instead, and confiteor to end your requiescat window.
here's a little visual, hope it's not too confusing! for the sake of being level 60, just imagine the atonements are a second royal authority combo. the main takeaway here is that you always want your dot ticking as much as possible, especially under fight or flight
just to put this in a bit of perspective, the potency you gain from your dot alone is about 985 potency total, 390 for the gcd + 595 for for all of the dot ticks, it's the highest potency skill paladin has (but i'm really bad at math sorry if i messed any of this up, this should mostly hold true though)
as far as your oath gauge and sheltron usage goes, just make sure you're not capping on gauge! if you reach 100 or are getting close to that, use sheltron whenever possible