A smile goes along way as well!
I have found that there are lots of moments between the B+G when they are getting the formals done, that the official tog doesn't get, so keep an eye out for them.
Not the best shot technically, but captured a moment when the main togs back was turned:
Also look for different angles of the formals. For example one wedding I was at the main tog had all the Hen Night ladies in a line flashing a bit of leg. He shot it from the front. I was able to get a shot looking along the line, so got all the girls and the legs from a different angle, which I thought looked good.
Also look for moments with the B or G and their family members - sisters, brothers, mums, dads etc. These are the shots the B+G will appreciate, a little look between the 2 sisters, getting a hug from mum, having a laugh with the brother etc.
Bride loves this shot (again quality crap, had to get it from facebook as not on this computer)
It's great to get the ones of the guests of the wedding, but it is unlikely they will make the main album.