Start with Coch-y-Bonddu Beetle (10-14) — on the bob / top dropper. Rainbows respond to more active retrieves — try short strips between pauses. If that does not produce, switch depth or speed before changing the pattern entirely.

Fish early and late, try deeper during the heat of the day with a fast-sinking line.

Evening tends to be the best period in summer — stay late if you can for a sedge or spinner fall.

Bank fishing near inflows, dam walls, and weed beds. Move to find feeding fish.