Ret Pally Button Mashing and Abilties

Retribution Paladins are often derided as "facerollers," and to be brutally honest with ourselves, that's not entirely inaccurate. If I recall correctly, the difference between the best priority system possible and the worst one starting with Judgement is only about 5% with 2 piece Tier 10, the kind of difference that gets eaten up in RNG. This is not to say that you shouldn't do your best to play well, because the better priority will still do more damage more often, but more as a point to be aware of.

The ability to mash buttons well is absolutely key. I know that sounds like an oxymoron, but in order to do Ret well, you should be hitting the button for whatever ability is next from about half a second before it comes off cooldown until you get the response from the server that the ability went off.

The first thing that should be said about abilities is that you should ALWAYS be hitting a button if you have a useful DPS ability available to you, with the possible exception of Holy Wrath. Delaying any ability in order to wait for a higher DPS ability is a DPS loss, even if you are waiting .2 seconds to hit Judgement instead of Exorcism. Seriously, just hit the button. Secondly, we give our abilities priority based on their DPS, not based on their damage per cast.

There are 3 priority systems, only one will apply to you, based on what set bonuses you have. These are all for single target dps. All of these assume access to at least Tier 9, since that is really easy to get these days.
2 Piece Tier 9 - Judge > HoW > CS > DS > Cons > Exo
2 Piece Tier 9 and 2 Piece Tier 10 - Judge > DS > HoW > CS > Cons > Exo
4 Piece Tier 10 - Judge > DS > CS > HoW > Cons > Exo

That should do it for a "rotation" guide. Any questions, comments, whatever, drop a comment and I will do my best to answer them or at least refer you to someone who can.