Ticks are definately an issue here in Oklahoma. I use a liberal dose of bug spray on the legs, arms and neck. Every time I stop, I also do a quick check of the legs and arms, the places that will most often rub up against things that give the little buggers a chance to jump on board. Back in the truck, I keep a change of clothes, a very wet soapy wash cloth and a towl. Along with ticks, we also get the added bonus of lots of poison ivy. Changing at the trail head gives me another chance to check for ticks in some other places and wiping down with a wet soapy wash cloth also helps find them, as well as decreasing the amount of poison ivy I put in my truck and carry home. Something that someone else mentioned above, if the hair on your legs looks like something akin to what you see on certain critters at the zoo, shaving can make a noticable difference. I know that I seem to have less problems than other people riding the same trails.
And last, the issue with tick and flea collars. The tick problem comes up very once in awhile on our local forum and last year, someone mentioned using some sort of tick and flea collar. A local doctor that rides, pointed out that dogs do not sweat, relying on panting to cool off. I can not remember his exact words, but basically tick and flea collars rely on the oils on a dog's hide to make the collars work. He stated the problem with a human wearing a collar would come about from the amount of sweat produced as we ride. This could lead to an excess amount of the active chemical on the collars being absorbed into the body.
Brian