If you are anything like me it's not too hard to be mindful when you're meditating, however, when you're doing things it gets a little tougher. I have found a good technique that helps me be mindful when I am doing mindless activities.
When you are doing an activity such as vacuuming ( I know that is a horrible thing to think about, especially for you younger people) use your other hand. If you are right handed use your left or vice versa. When you use the hand that you normally don't use it's easier to feel the muscles being used keeping yourself in the moment, and you have to concentrate more one what your doing. Like when you try and write with the wrong hand. You can't think about the sentence your writing you have to live in the moment of writing each letter. The same is true when doing anything different even trying to chew food on the other side of your mouth. You can do this with almost anything washing dishes, playing catch (Have you ever tried to throw a ball with your other hand?), even sitting in a chair with your legs crossed. Whatever you would do normally, purposely do it the other way. If you normally put you left sock and shoe on before you do the other foot, purposely put your right sock then left sock and then your shoes on. I think you get the point.
I know what your saying right about now something like "I can vacuum with my other hand no problem this won't keep me mindful of what I'm doing!" I have to tell you that no matter how well you can do things with your other hand or foot or whatever, the minute you stop thinking about what your doing you will sub-consciously will go back to your normal side. That is how you will know if you are being mindful or not.
Give this a try trust me if it does nothing more than make a mindless job a little more fun it will be worth it. And it will also give you more control and strength on your other side. That's always a plus! ;D