Roses bloomed (wins), buds are promising (opportunities), thorns hurt (problems). The bud column makes this gentler and more forward-looking than most three-column retros.
Explain the three columns: rose, bud, thorn.
Everyone adds notes to all three columns.
Read notes aloud and cluster; celebrate the roses briefly.
Pick the most promising buds: what would help them bloom?
One action to grow a bud, one to remove a thorn.