Video Tutorial

Row 1: Chain 3
Row 2: 2 half double crochet in the foundation chain
Row 3: Star with chain 2, 1 increase, finish with 1 half double crochet to the end
Row 4: (Lace row), chain 3, skip 1 sttich, 1 half double crochet, *chain 1, skip 1 stitch, 1 half double crochet* Repeat to the end where we make an increase
Row 5: 1 increase, half double crochet to the end
Row 6: half double crochet to the last stitch, where we make an increase
Row 7: (Lace row), 1 increase, *chain 1, skip 1 stitch, 1 half double crochet* Repeat to the end
Row 8: half double crochet to the last stitch, where we make an increase
Row 9: 1 increase, half double crochet to the end
Row 10: Repeat row 4
Row 11: Repeat row 5
Row 12: Repeat row 6

Continue repeating rows 4 to 9 to have the size needed

Once you have the size, repeat the same rows but instead of making increases, make decreases