Many teams hold retrospectives faithfully and still repeat the same problems. The missing piece is almost always follow-through.
Begin by reviewing the actions from the previous retro. Did they happen? Did they help? This simple check signals that the meeting has consequences.
Vary the format to keep thinking fresh: start-stop-continue, a timeline of the sprint, or a "sailboat" exercise with wind and anchors. Then group the themes and vote on the one or two that matter most.
Limit yourself to a small number of actions, each with an owner and a clear first step. "Improve communication" is not an action; "post a daily summary in the team channel by 5 p.m. for two weeks" is. Put the actions on the team board alongside regular work so they get the same attention.