I personally work to cleanse the environment first, then the person under the theory that it is more difficult to maintain purification of self if the environment you are in is miasmic. There are several things that one can do for this. First, and foremost, a person should literally clean their home. This would seem self-evident, but it is not always so. The act of cleaning the home IS a form of purification. After that, water with sea salt in it can be sprinkled around the home and incense burned to cleanse the home on the spiritual level.
The mention of sea salt brings me to the purification of body. One of the most effective ways that I have found of purifying the person involves a bath (showers will work in a pinch but an actual bath is better) with sea salt in the water. This echoes the way that certain temples would ritually purify the cult image by bathing it in the sea. Also, with a bath or shower you can visualize the impurities going down the drain. This may seem overly simple, but I find that it is effective. Also, people can fast for purification purposes, but this is not necessarily good for everyone due to people’s varying dietary needs. Traditional religions recognized this and there are prohibitions for people with certain medical needs from fasting. For example, pregnant or nursing women and diabetics should NOT indulge in a complete fast. Despite this, fasting from one or more things that you enjoy for a day can be a purification.
There are other things that can be done for purification purposes and I know that I have only scratched the surface. Self-purification and purification of the environment should be done regularly and not just for festivals but doing it for festivals is at least a start for most people……