I'm not sure how I feel about sewing swimsuits. The suit I used to have (store bought) lasted a long time. Last spring (2011) I bought a new one since the old one was worn out and I was cutting it up to make a pattern and I wasn't sure how that would work. That store bought suit lasted only about six months! The one I made at that time, with fabric from FabricLand, is still going strong, although I didn't wear it a whole lot. Then I sewed two suits in October. One has worn out! It was fabric I bought at Value Village, so I guess I can't complain too much. And it's too big now.
Meg needed a new suit, since she's in the hot tub a lot and her old suits were hand me downs that were really worn out. She wanted a tankini, and I used the same Kwik Sew pattern that I used for Lucy's suit (I don't think I've used it as intended yet). Her measurements are all over the chart though. I had to lengthen, widen some, narrow the shoulders....when it came time for adding elastic to the arm and necklines...I had no idea what to do. I compared the original amount to the original pattern, and it used about 1 1/2" less elastic then the measurement. That did not work. I took elastic out. I added elastic. I ripped and re-sewed. Finally, it seemed okay. I hope no one ever unpicks it and sees how I added in and cut out bits of the elastic! LOL.
Another big issue I had...when I cut the front, I added two inches to the length...but I didn't mark it on the pattern. When I cut the back...I forgot to add that extra....yeah. I've done that before, and still haven't learned. So, I ended up cutting a strip to make a ruffle. The length wasn't bad before, but she did want it to cover her belly completely.
The fabric was from Spandex World, last summer. I ordered two yards, and was very disappointed when it came and there was a white line between each yard. But it was cheap, compared to what I can buy here (and they don't have the swim suit material "mill ends" bin anymore!).