We need to keep ticks off the dogs particularly because we regularly have small children in the house (childcare, visitors; ours is fledged).
We go hiking east of the Cascade crest in spring:  Cle Elum/Teanaway area, Leavenworth, Chiwaukums, Vantage, Umptanum Ridge, Chiwawa R., that seems to be where we get them.
Recommendations?  If you sun-spoilt east-siders can tell a mouldy Seattleite what you do for ticks, I'll tell you how to keep moss from growing between your corgi's toes.
We have used Advantix, apparently effectively, but sometimes I wonder about the permethrins.
We've used Advantage effectively for fleas.  Can one alternate Advantage with Advantix?  Use Advantage for fleas, and then -- if it's wearing off -- switch to Advantage with the permethrins if a trip to the east side is in the offing?

Reading Joanna Kimball's blog, she doesn't like permethrins (Advantix, Bio-spot etc.) but mentions this Comfortis, a new chemical, Spinosad, pill form, allegedly kills fleas for a month and kills ticks for a week.  At first, I thought this might work for me; I could dose whichever dog is going "out east" with Comfortis on an as-needed basis, instead of keeping both dogs loaded up with permethrins all the time.  But then I realized that this anti-tick window is too brief to be practical, and I don't want to be mixing chemicals. 
Anybody have experience with Comfortis?
Here's a blog with some quite scary anecdotal observations (including fatalities) about Comfortis; anecdotal observations are notoriously unreliable and suspect, but:
http://www.dolittler.com/2008/3/29/cat.dog.flea.vet.pet.veterinary....

http://blacksheepcardigans.com/ruff/?s=permethrin&x=0&y=0