First of all, you should choose the place or places of fishing. If the river or pond is well known to you then everything you have a clear chance of catching fishes. But if you're going into uncharted territory, better to bring a depth sounder. This device will help you recognize the bottom relief, as well as detect the presence of fish.
If there is no sounder, carefully inspect relief coastline. Pay particular attention to the ravines and elevation changes, springs and flowing rivers, carrying with them a lot of oxygen, the island and the peninsula, forming shoals and braids.
Decide whether you want to actively search for fish or keep waiting for hours. These two methods bring success in different conditions. In winter, when fishing, trolling, it makes sense to look for fish constantly active.