In the summer I get on the water at daybreak,and fish to mid- morning.Or I fish the last 2 hours of the day,or at night.From 10-6 it's hard( on me and the fish.)The fish get very lethargic here in the summer,so the key is to fish SLOW.I catch a fair amount of fish early in the day,using my favorite plastics.I have several that I rotate so the fish don't get too used to them.Sometimes I will try something new that they haven't seen before,or an unusual color.
If I'm still out when it gets hot,I fish shade,esp.skipping under docks.4 inch senkos are great for this.I also usually pick up a fish or two on small,isolated weed patches out away from the bank.
If you think about it,fish have to eat to survive.So they still will bite when conditions are extreme.But you must put the bait where they are,which is often the hardest place to get it to in summer.Because they won't chase it very much in the summer.It expends too much energy for the return they get.
Another summer strategy is to find a deep hole and fish it very slowly with a 10-12 inch worm.I mean cast it out and let it sit for 5-10 minutes.I once caught a 6 pounder after letting a big Mann's jelly worm sit there for 15 minutes!.and I caught 4 fish 5-6 pounds in the same hole that summer .
Big bodies of water can be overwhelming so I would start small.Fish small water ponds/ lakes.The fish are more concentrated.If fishing a big water body,I would focus on a few areas that have structure with deep water nearby.Learn to fish them well,then expand your area.
Keep at it and you'll succeed!
Mike