some great ideas. I like the paddle mounted sticker.
Tape measure from Target or Wall-mart works good.
My old gaff is is marked with electrical tape on 12", 22", 24", 28" - works too.
WSB min length is 28", halibut 22", YT has no size limit. When you see how mighty YTs grow to be, you get a kick out of letting little ones go. You've got to be aware of limits on WSB you can keep, as they change 3/15 to 6/15 where you can only keep one.
Nice DFG CA map page that drills you to summed up regs per species for your region:
http://www.dfg.ca.gov/marine/fishing_map.asp
South CA
http://www.dfg.ca.gov/marine/mapregs5.asp