1.  Vacuum your carpet often or at least 3 times a week.

2.  Use a good quality vacuum, and don't forget to check if the bag is full.  When the bag gets full the vacuum loses some of its suction.

3.  If possible avoid wearing shoes on the carpet.  Not only will this help keep the carpet cleaner, but this will also lessen the wear on the carpet.

 4.  Keep a rug or mat at each entrance of the home or office.  Lots of debris sticks to the bottom of our shoes, including parking lot black top residue, small rocks and gravel, gum, etc.