Mermaid Tail Blanket

I tried one of the patterns given for the mermaid tail, (the child one by Marta Stelter). I do not do fussy patterns and as a result, I frogged it about 10 times! I am frustrated! I found a video that explains how to make a really nice tail and now I thought I would try a different body. I was hoping to do a feather and fan type pattern, but I do not know how I would go about that because I intend to knit on round needles and if I start top down I will have to decrease or bottom up and increase- but I don’t know how to go about decreasing and increasing in a feather and fan pattern. Is there anyone who has or can make up a feather and fan mermaid tail pattern for knitting? (Most of the ones I have seen are crocheted). Thanks in advance.

It may be best to change from the feather and fan for increases or decreases. Work in something sturdy like garter and make the inc/dec over a row or two at the body tail junction.
You’re thinking of making both the top and the tail in feather and fan? I’ve seen tail patterns in rib that worked quite well and didn’t have problems with curling.

Thanks, I found a pattern that is just knit and it is fun too- I started making 2 at a time! Anyway, I am making one that is self striping, (color blocked) However, I was wondering about the fin part: Is it from fins (one on each side) up, or from cast on edge down? ( I hope this is clear, but I need to know because of my color sequence)

The fin is worked flat from one side to the other. Cast on, decrease several sts on one edge until only ~one third of the sts remain, then cast on several sts each row till you’re back to the original stitch number.

I understand, but maybe my post was not clear. Am I knitting the fins first (bottom up) or is the pattern showing that it is from where I sew it, down to the fin? Again I am just concerned about mixing up my colors and I am afraid I don’t quite understand how to go about it.

You could knit either the body first, top down or the fins. Each is separate (body and fins) then joined.
Is that what you mean?

I think I might have answered this since I was thinking about it more… It says cast on and if you knit 3 rows, clearly you are starting at the place where you would sew it together… at the top of the fin, not the fin itself, so that is just what I wanted to know!

Do you mean where you cast on tor the fin as opposed to the body? Where it says cast on and then k 3 rows (garter stitch)?
What do you mean by “sew it together”? Sew the fin together or sew the fin to the body?
See the note that precedes these directions about “tailfin is worked side to side…”