I am trained in Classical Feng Shui and use Flying Stars which is the most accurate system of Feng Shui. Cleaning out clutter helps to allow the qi to move through the space, but getting the current-period qi into the dwelling is the most significant way to handle problems and to maximize that building's potential for health and wealth. While 'intention' may play a part in the other systems, it does not with the Flying Stars; neither do crystals nor baguas.
Since so many books on the market are quite confusing, I chose to study with Master Joseph Yu who starts everyone off with his correspondence courses which do address other systems of Feng Shui as well; then, we attend his seminars, of which I have attended several, including both the Advanced and the Professional level of Feng Shui for the Flying Stars. He is a superb teacher and is one of the top three Classical Feng Shui Masters in the world; he continues to do original research on Feng Shui, as well as on the readings of the ancient Chinese texts.
I have also studied Four Pillars Chinese Astrology at an Advanced level with Master Yu.
Feng Shui would have about 20% influence in one's life, while Destiny influences 50% and what we do with what we've got would influence 30% of one's life.