Since we are talking specifically about a Paladin in this case lets start by looking at the skills he has and tricks available already. Skills - Concentration (Con), Craft (Int), Diplomacy (Cha), Handle Animal (Cha), Heal (Wis), Knowledge (nobility and royalty) (Int), Knowledge (religion) (Int), Profession (Wis), Ride (Dex), and Sense Motive (Wis)
It's a pretty poor skills selection for tricks which are mostly based on Balance, Bluff, Climb, Jump and Tumble, all of which are cross-class for a Paladin, even a fighter could be more tricky.
Healing Hands (Heal) and Dismount Attack (Ride) are the only two he's likely to pick up without multiclassing or being at least 7th level, and with only 2 skill points a level it's likely he'll need to be higher than that to get even the most basic ones.
None of the skills he has really lend themselves to designing tricks, except perhaps Ride. So I was thinking riding tricks like in the westerns. Sitting backwards in the saddle seems like a good trick until you realise there is no facing in D&D so a house can run at full pelt in one direction, turn on a six pence while you fire your arrow, and then turn back and charge on without any additional penalty that would be offset by such a trick. Somebody who knows more about trick riding should perhaps have a go at making some of these.
Sense Motive might work for tricks. If you beat an opponents Bluff check when they try to Fient you, you can sucker them into believing they have fallen for the bluff, but then hammer them for say bonus damage or treat them as flat-footed or something. That's the sort of thing that suits a trick as an opponent isn't likely to fall for it a second time, hence once an encounter.
The other skills don't really seem to suit tricks.