Your best Reels show the gap between the setup and the shot. Name that gap in the hook, then let the result land at the end so people stay for it.
Quick answer
Pick one line below, swap in your own words, and put it in the top third of the frame for the first 3 seconds. One idea, two short lines. Each group opens a matching template in the free maker.
Use your own words. These are starting points. The version that sounds like you, or quotes a real client, always beats the template line.
Match the hook to the first frame. If the line says "watch this", the first frame has to show it. A hook the video doesn't pay off loses people at second 4.
Keep it readable. White stacked pills (Classic) read over any footage. Bare text needs a calm background.
Stay out of the bottom. The caption and buttons cover the lower part of a Reel. See the Reels safe zone guide.