Both lakes are plentyful with each. Finding the right spot is the hardest part - look for a gravel bar with about 3 to 4 ft of water on it, but drops off deep on both sides. Many like using crickets and worms, but I've found that using a small minnow is best and reduces the number of baby fish that you catch - also gets you some good bonus catfish and bass.
I feel like Barkley gets less pressure since there are fewer lodges/resorts to choose from. The big bay of Kuttawa Harbor has a lot of gills and crackers in it if you know where to look A few bays within a mile of the breakwall also hold good numbers as well. The Oasis near there has good steaks and is one of the few places to have a beer.