1st piece of advice, get out of Crecent ASAP, and Don't camp down by the beach. Lots of tweekers and weird people there. Easy ride from there to Orik or Arcata/Eutweeka.
Second peice of advice. Only go to Eutweeka for food/soup kitchen/busking/etc during the day, it's called Eutweeka for a reason. And don't camp there, stay in Arcata, easy hitching between them and a cheap bus.
Arcata is great, lots of travelers and places to camp in the Redwoods.
Semi-easy hitchhiking Eureka to Willits/Ukiah from there. Garberville is a worthwhile stop along the way to meet travelers.
From there it's a straight shot to Cloverdale/Santa Rosa/Novato/San Fran. All of the towns around there have cheap public transpo to San Fran.
If you take the Ft. Bragg junction over to the Hwy 1, it will see less traffic, but much more scenic. Just got info, hitching from the Point Reyes area into San Fran is difficult, and the park Rangers will stop you. Illegal to hitch in that park.
Have a great trip! Wonderful route.