Pallies are a pretty fun class and quite powerful too. I have never tried Ret actually. Anyways, Grimbeorn got me to work on my 969 rotation for pally tanking and I think he got it from Sandric. Most of your spells/power shots have a cooldown of 6 or 9 secs. You bascially want to fire off a 6 sec cooldown (ie- Hammer of Righteousness/Shield of Righteousness), then a 9 sec cooldown (ie - Holy Shield, Consecrate, Judgement Wisdom), now back to a 6 sec cooldown (ie- Hammer of Right/Shield of Right), back to a 9 sec cooldown (ie - Holy Shield, Cons, Judge Wisdom) and just rinse and repeat the cycle of 6969, whatever ability is up.
These are some nice clips, making a macro would make it really easy.
http://www.youtube.com/watch?v=SPJP-LE2dIE&feature=fvw
http://www.youtube.com/watch?v=17gYjce4P7E&feature=related
Also, remember to have your Righteous Fury/Blessing of Sanctuary on @ all times and a Seal (most guys like seal of Vengence). I like Veng too, but I find it runs out of mana fast. I like Veng in raids because there's lots of mana regen buffs in raids, but for heroics I like using the Mana regen seal (seal of wisdom?). You also have this ability that gives you 20% more dps and it has a long cooldown (2 mins?), that's a good one to pop @ the beginning of boss fights for extra aggro.
Anyways good luck pally tanking and have fun.