There are lots and lots of cute and simple baby hats out there. Here’s one that I made up.
Hat for 2-4 month old baby:
5mm hook, light weight yarn.
Rnd 1: ch 2, sc 6 in second ch from hook (6)
Rnd 2: sc 2 in each sc around (12)
Rnd 3: [sc 1 in first sc, sc 2 in next sc] repeat around (18)
Rnd 4: [sc in each of next 2 sc, sc 2 in next sc] repeat around (24)
Rnds 5-9: continue this pattern, increasing by 6 each round until you have 54 sc around
Rnd 10: sc in each sc around (54)
Rnds 11-23: repeat previous row 12 times (Optional: crochet rounds 15-16 in a different color)
Rnd 24: (For boy’s hat, omit this round and do one more repeat of Round 10) sl st into first sc, ch 3, dc 2 in same sc, dc 3 in each sc around (Optional: crochet this round in a different color)
Fasten off. Weave in ends.
It’s so easy to change this pattern to fit any head or work with any yarn. Just add more or leave out some increasing rounds and even rounds.