I've caught quite a few this year. Once the water got warm the trick was to find deep water docks with a dock light. Look for a dock with a mercury light close to the water. Also, those fully automatic boat covers create a good shade. Look for big slips without a boat that have shade.
PK seems to be different than most lakes for crappie. It's a flooded cedar forest so structure does not mean much to crappie. I catch them in cedar tops sometimes but shade seems to be the thing.
As for bait, minnows seem to work the best once the water is over 15 feet. If you are fishing a jig, tip it with a minnow. Dead or dying minnows work better than live ones. Rather than holding it still pitch it out and let it arc back to you. If the water is really clear you don't want the crappie to get too good of a look at your bait.
Don't get discouraged by perch. Usually in Fork or Ray Roberts, if I start catching perch it's time to move. At PK, they run together. When the lake was super clearback in may/June I could see the schools of crappie and perch swim by in the deep dock I was fishing. Once they passed, I could see they were slowly followed by several very big LM Bass.
John 21:3 Simon Peter saith unto them, I go a fishing. They say unto him, We also go with thee.