Use a fill‑in‑the‑blank template. It keeps things simple and fast.
Step 1: Pick a structure
“Happy birthday, my [adjective] [son / champ / star]. You [verb phrase].”
Step 2: List 3 adjectives about him
Example: funny, brave, kind.
Step 3: List 2 things you love he does
Example: “make us laugh”, “work so hard”.
Now plug in:
“Happy birthday, my kind champ. You make us laugh every day.”
Count characters, trim if needed.