Be an athletic supporter.

Support your partners interests and cheer for them wildly.

          Does your partner participate in a sport or hobby regularly.  Maybe they are on a softball team or attend yoga classes.  If so how much to you support there activity.  Do you ask them how they did when they return home?  Do you ever attend and cheer for them during their activity?  Do you understand their activity?  These are important questions to ask yourself.  It should be obvious that they enjoy their hobby but without stepping over the line, get involved.  Don't join their softball team but do go watch and cheer when they do well.  You don't have to attend yoga class with them but ask for some insight when they get home.  Heck ask them to show you a pose or two would be fine.  The important thing is to show they that they are important to you and what they enjoy interests you.  It's great if you can find something that you can enjoy together.  However, sometimes you have to just let them enjoy their passion and then let them share it with you via conversation or watching.