a couple of thoughts...
1. cute pose, as has already been mentioned a common way of doing this is with the ring in focus and them not. I think by doing that their hand being there would make more sense. As it is, you have a part of their body sticking towards you that is completely out of focus. Just kind of odd. Also, because their heads are so close together it kind of squashes her face.
My one other thought about this, is that it may look a bit better with some more contrast... just a little more pop.
2. Decent shot, I think here I generally prefer the girl to be in front, but if you want the guy in front that's fine. One thing I've learned is it's helpful to at least somewhat pose the back person. Have them doing something with their hands. maybe cross the arms or have them resting on her side, or something. You could also make her rock her shoulders back a bit (she looks like she's hunched forward a tad) general have more of her weight on her back foot, and turn her a bit from the camera so she doesn't have the manly vibe going on.
3. Good shot again, but it's ruined by the ring not being in focus. Again, if you're clearly showing the ring it needs to be in focus. Going to more of an f/8 or f/11 or something probably would have helped. The contrast in this one is better than in #1 (from my crappy work monitor)
4. very cliched pose, but clients seem to like it... so whatever. I do this one frequently, and one thing I've learned is to try to avoid having the double chin showing up. You did a good job of hiding it on the girl, but you may want to do some PP and get rid of it on the guy.
5. Nice shot, probably my favorite of the set. but then, I'm a fan of these kinds of shots. I wish she was wearing this coat and boots in number two. Because in number two the legs are kind of distracting.
The one other thing I noticed is that her eyes generally looked a little funky. One is more open than the other. I know there's not much you can do about that, but if you notice something like that, it might be helpful in posing her more so that you see only one of the eyes, or to kind of hide the difference. Try to show the their best sides and they will generally be happier.
Overall not a bad set. These are just my ideas for improvement... take them with a grain of salt.