You can look at it however you want – collaboration, keeping the peace, showing your love – but when it comes to designing for his and hers, it is really about compromise. Now that may sound a bit cynical, but in reality both parties can’t have their ideal design as everyone has different tastes. But that is not to say that you can’t make things work and be exciting for everyone.
Personally, when I think of “His & Hers” design, I immediately imagine double sinks and monogram towels. The bathroom really is the easiest place to think about such design considering men and women often have different routines in there. In designing a vanity for two people, size really does matter. There needs to be ample space for both parties as well as room to place or store their various hygiene “equipment.” Secondly, bigger is better with mirrors. Though it may not be as budget-friendly, one large mirror spanning both sinks has a few advantages over two separate mirrors. For one, the extra reflective surface allows you to see much more of the room behind you. If you both happen to use the space at the same time, you have a better view of your partner as he or she prepares for the day. Also it is much easier for men to flex in front of a large mirror when they are alone.
As far as the rest of the home, possibilities are endless yet restricting. Ideally, both people need to agree on the way to design their living spaces. Sometimes this can result in so many compromises that the home turns into a bland, no-one-got-their-feelings-hurt kind of beige. Not to knock it if beige is your favorite color. The point is this: look for ideas together and put them into motion together. Communicate with one another about what you like and don’t like. Hopefully this will lead you both with less of a feeling of “I can live with this” and more “I want to live with this.”