Tip no.1 : Be prepared. What I mean by this is that you wanted to start by scouting the location if possible to charging all your batteries.
Tip no.2 : Get inspirations from others -> lookup other wedding photographers and see their work, observe carefully the pictures that you like and analyse them accordingly (like what focal length did they use, depth of field, lights and how they composed the shot). Of course you will encounter a different situation but the concept might somewhat be helpful.
Tip no. 3: Try to keep on talking to them (politely of course) and telling them what you want them to do (aka posing them).
Tip no. 4: It's got to be the light, how are you going to light them. During a wedding, you can't really bring too many lighting gears (booms, umbrellas and softboxes) and also you just don't have time to set them up. Tip no. 5: Bring in another photographer as it might save your life, :).
Here is the first shot that I would like to share :
Now for this next shot, I had them (bride and groom) together and it was dark, I saw that the car was a lonnnggg limo (hemm pretty cool). So I thought to myself, hhehmmm let see where I can place them around this cool thing. Here the composition was somewhat ordinary (nothing fancy). As for the light, I realised that when I placed them besides the limo, their faces will be dark so I had the VAL to bounce the flash on the side-wall to create an even light on the pair. To create another dimension to the photograph, I had the headlights of the limo to be turned ON. Okay guys, I hope this short article would somewhat be helpful in a way.