I've found the Seresto collar works on the dog. I had a cheap flea collar on the cat, but it's not working, so I ordered a Seresto collar for the cat yesterday. Expensive, but I want something that works!
I do a lot of vacuuming and washing the blankets they lay on too.
I don't use chemicals on my animals anymore. We tried the frontline like I mentioned, against my better judgement and it turned out badly which just reinforced my resolve not to use chemicals.
We just comb the cats and dog 4 or 5 times a day during flea season and 2 or 3 times a day in the off season cuz the little suckers hang around even in the winter. Then I use rose geranium oil (dilute) to help prevent and then a few other tricks, we rarely have an actual infestation, they will get a few on them no matter what you do.