Make a foundation chain of 78 chains or multiples of 4 chains plus 2 additional chains.
Join it into a ring with a slip stitch.

1st round – ch1, sc1 into same ch., dc1, [sc1, dc1] to end + sl.st.1 into 2nd ch

2nd round – ch1, sc1 into same ch., sc to end + sl.st.1 into 2nd ch

3rd round – ch1, sc1 into same ch., fp dc1, [sc1, fp dc1] to end + sl.st.1 into 2nd ch

Alternate the 2nd and 3rd rounds until you crochet about seven rounds.

Use a larger size crochet hook to widen the garment.

Use a larger size crochet hook to widen the garment.

8th round – sl.st.1, ch3, [fp dc dec 1, Vst1 above last dc of dec.] to end; unfinished dc1 under last dc post, unfinished dc1 under ch. between dcs, unfinished dc1 under 1st dc of the round, dc1, ch1, sl.st.1 under initial chs

9th round – ch3, fp dc dec 1, Vst1 into Vst, fp dc dec1] to end; dc1, ch1, sl.st.1 under initial chs

10 – 17 rounds = 9th round

Decrease
18th round – ch3, fp dc dec 1, dc2 into Vst, fp dc dec1] to end; dc1, sl.st.1 under initial chs

19th round – ch3, fp dc dec 1, dc1 into Vst, fp dc dec1] to end; sl.st.1 under initial chs

20th round – ch2, work fp dc dec reusing dc of previous round to end; sl.st.1 under initial chs

Use a smaller size crochet hook.
21st round – ch2, (unfinished dc under middle dc of dec., unfinished dc under chs between decs) x 2, draw the yarn through 5 loops on hook, *unfinished dc under same ch, (unfinished dc under middle dc of dec., unfinished dc under chs between decs) x 2, draw the yarn through 6 loops on hook. Repeat from * to end; sl.st.1 under initial chs

22nd round – ch2, (unfinished dc under 2nd middle dc of dec., unfinished dc under chs between decs) x 2, draw the yarn through 5 loops on hook, *unfinished dc under same ch, (unfinished dc under 2nd middle dc of dec., unfinished dc under chs between decs) x 2, draw the yarn through 6 loops on hook. Repeat from * to end; sl.st.1 under initial chs

23rd round – fp dc dec1 under middle dcs of decs
Cut the yarn and secure it.