The Staged Shot
There's a reason why one of the most popular types of photos is the staged shot. It's simple, cheap and you don't have go anywhere!
All you need is your significant other and your home. Provided you have that, you'll be set to go. Just choose the particular location. Maybe you'd like to take the photo outdoors (say, to show off your new home), or perhaps near the fireplace if you're planning a holiday picture. Just don't forget, you'll want to make sure you're still the highlight of the picture -- not the fancy new paint job in the living room.
No matter how much you stage a shot, there is no substitution for the original, which is where our next couples' photo idea comes from.