(Note that these are inspired by something similar on Pinterest; I have only seen the photo of those and have no real clue how they're made. These don't look exactly the same, and they're not supposed to. Barefoot sandals aren't a new idea, but making them for a baby/toddler is pretty unusual, so I did not want to copy them exactly.)
4.5 mm hook
small amount worsted weight yarn (sample uses Simply Soft)
special stitch: Elongated Dc (ElDc)-YO, insert hook in st indicated. YO, draw through ONE loop on hook. YO, draw through 2 loops on hook twice.
ch 4, join into a ring
1) ch 1. Sc twice. Hdc twice. Dc twice. Ch 2. Dc twice. Hdc twice. Sc twice.
2) ch 1, turn. Sc in each sc, Hdc in each Hdc, Dc in each Dc. Elongated Dc, ch 2, ElDc, all in ch 2 space. Dc in each Dc, Hdc in each Hdc, Sc in each Sc.
3) ch 1, turn. Sc in each Sc, Hdc in each Hdc, Dc in each Dc. ElDc in ElDc. ElDc twice, ch 3,ElDc twice in ch 2 sp. ElDc in next ElDc. Dc in each Dc, Hdc in each Hdc, Sc in each Sc.
4) Ch 26. Sl in 2nd ch from hook and next 24 chs. Working across sides of rows (bottom of sandal), slst in each row across to other side. Ch 26. Sl st in 2nd st from hook & next 24 sts.
ch 4, join into ring, leaving a long tail to sew with.
1) Sc 8 times in ring
2) Sl st in first st. Ch 3. Skip next st, slst in following st, ch 3 around. (4 ch 3 spaces)
3) Ch 1. In each ch 3 space: Sc, Hdc, Dc, Hdc, Sc. After finishing fourth petal, slst to first Sc. Finish off.
Sew flower to leaf top, using long yarn tail.
I made these to fit Marie, who is 19 months and has big feet. There are several ways to make them smaller if desired: leave off row 3 of the leaf portion, or use sport weight yarn & a 4.25mm or 4mm hook. Or just let them be a bit bigger on a smaller baby.
I used the elongated DC (which you may know as a herringbone DC) instead of a treble crochet for two reasons: one, it is faster, for me anyway, & two, it created a bit of a gap in the leaf which I found unattractive. If you prefer, you can use treble crochet instead, or simply use additional DCs.
Another way to finish these would be to finish off the leaf after row 3 and thread a narrow ribbon along the bottom portion of the leaf (the flat side) and use that as a tie.
If you'd rather a 5- or 6-petal flower, start out with 10 or 12 sc in the ring. If you do, you might want to start with a 5-chain ring.