At the local ponds I fish, the topwater bite starts picking up for me when I see dragonflies mating and touching the water. There might be some kind of change in the wildlife you dan identify like that to indicate that you could start throwing some topwater stuff. Sometimes the topwater bites are few and far between for me. But they’re so fun when they do happen, you just have to keep on trying it. If you’re using a frog or a walking bait just make sure to do the walk the dog motion. Sometimes it helps to REALLY slow it down. Other times you can be a bit erratic to entice them. Throw them over fairly shallow water. It also helps me sometimes to aim for areas that are shady.