The biggest thing is just moving more, unless you're trying to build strength, power, muscle, etc. . .
I've lost a lot of weight since one year ago. Diet is a part of it (portion sizes tend to be smaller in Japan), but the biggest part is just being more active. I have to ride my bike or walk to the train station every day, I'm physically active at work (picking up kids and almost always standing), and on my days off I usually walk even more than usual. In fact, that's one of the main reasons I like to go to the mall so often in winter.
I think for those people working at desk jobs, a good thing that more places are starting to implement is the standing desk. That's a huge difference. That small amount of calories constantly being burned adds up and is more important that going to the gym once a week. Quantity often wins out over quality when it comes to physical activity. More constant activity means more consistently high metabolic rate.