Rule number one: No guns in shot.
Can't stress that one enough.
No snakes or iguanas either.
Ensure everyone is appropriately attired.
Or puts a shirt on, at least.
Make sure the groom remains calm.
Do not, under any circumstances, get photobombed by an alpaca.
Or a horse.
Or a beluga whale.
Or a cat.
Or two humping dogs.
Or a sloth.
Or this couple.
Or Death.
If the groom wants to ride the bride like a horse, politely discourage him.
If horses must be involved, choose your steed with care.
And be wary of this sort of thing.
The whole "miniature bride" effect is not ideal.
In fact it's slightly unsettling.
And even when the tables are turned, it's still not a good look.
Marriage is a sacred occasion, so cultivate a sense of sober refinement at all times.
Dignity. Always dignity.
Use Photoshop sparingly.
Because, really, you're not fooling anyone.
Make sure every member of the wedding party shows how deliriously happy they are.
Scope the area out beforehand to avoid embarrassing mishaps like this.
Or this.
So choose your venue with care.
This last point is worth reiterating.
But most of all, it's your special day, and you'll be looking at these photos for the rest of your life - so remember to put on a happy face.