Thought I would share this article which speaks about dealing with fleas without chemicals.

http://healthychild.org/uploads/File/29128_flea_bmark.pdf

Does anyone have any other tips to share?

There are a lot of safe, efficacious products that combat fleas.  I like diatomaceous earth (not pool-grade) and pyrethins (derived from the flower heads of several types of Old World chrysanthemums) in various delivery systems, such as powders or shampoos.  Another product, d-Limonene, is a by-product of the citrus industry and carries a mild, grapefruitlike odor.

Many dogs and cats seem to benefit in the fight against fleas from the addition of garlic and brewer's yeast to their diets. When these substances are metabolized, an odor (and flavor) that fleas find very unattractive develops in the skin.

Hi Dr. Brown:

How much garlic and brewers yeast is recommended. Is it one or the other or both that will support the health of your pet?

Both are quite variable, depending on who you reference.  Bob Goldstein DVM recommends 1 - 4 cloves of garlic per day depending on the size of the dog (I don't recommend garlic for cats).  The dosage of B-vitamins is 50-150 mg per day depending on size.