You might look at some of the smaller lakes south and west of Ft. Worth, otherwise you'll need to head south to Cedar Creek to find really good docks.
Not sure who you "heard" that from, but...
The truth is that dock shooting is best post spawn-early summer (April-June) and again in October (sometimes an even better time). I'm not saying you can't pick up a few under docks this time of year, but the higher water temps push most out into deeper water.
Go to Cedar Creek in October or May, and I promise you won't be disappointed.