Two kids, one husband and a dog = a house that doesn't always smell as fresh as I would like it too.  But I found this great way to make my house smell incredible while doing something that needs to get done anyway.  I just take a cotton ball and add a few drops of an essential oil I love (I prefer grapefruit or lemon in the summer and cinnamon or ylang ylang in the winter) and vacuum it up when I do my vacuuming.  Then as I vacuum the entire house, that scent is released into the air and then not only is everything clean, but it smells great too!