I like a long dock in deep water
look for the dock that has shalow water, some structure other than the posts ( brush pile, jet ski rmps etc)and transistion to deep water all in one. allot docks in texas are rather shallow ie...a 20 yard dock that goes from the bank to 4' in 20 yards. Eagle Mountain is a good place to learn to fish docks and what to look for. Some there go from the shoreline to 20' deep in 20yds! I try and fish that one dock that sits out from the others and has some rip rap around it or some strange structure under it (sidescan). Work every post on each side and fish it completely if you think there are fish there. I have cast to one side of a 8"dock post several times and then hit the other and immediately got a bite. Im not a jig guy so i usualy throw and Trig craw or something like that around and under the docks i fish...SteezMacQueen is on the money also! if you can skip a bait under them! most swim baits will get your arm broke off!
Go home at the end of your shift, no mater the cost!