How to Make a DIY Swimsuit - Cute Bow-Tie One-Piece Edition!

Edgewater Avenue
by Edgewater Avenue
9 Materials
3 Hours

In this tutorial, I'll show you how to make a DIY swimsuit with cute bow-tie detailing! This one-piece bathing suit is so chic and elegant, and it's actually really easy to sew. Grab your favorite swimwear fabric, download my Cartier onesie swimsuit pattern, and let’s start sewing!

Tools and materials:

  • Swimwear fabric
  • Elastic
  • Cutter
  • Scissors
  • Sewing machine 
  • Thread
  • Chalk
  • Pattern
  • Strap adjusters - optional
How to make a swimsuit pattern

1. Cut the pieces

Transfer the pattern onto paper, then cut two of each pattern piece and four for the top breast piece out of your swimsuit fabric. Also, you’ll need some straps. So cut two strips that are 1.25 inches x 20-25 inches. 

When cutting the breast pieces, flip the pattern to get both the right and left sides. 

How to sew a swimsuit

2. Sew your swimsuit pieces together

Take the front pieces (both the top and the bottom) and match the printed with the printed, and the lining with the lining. 

Sewing a one-piece swimsuit

Right sides together, pin the breast piece to the bottom piece. And sew them 1.5 inches in, just enough to make them attach on the sides. If you don’t have a serger, use a zigzag stitch. 

How to make a swimsuit

Now line up the back piece to its corresponding front piece. Then, sew the sides together at the part just above the hip and the curve of the waist. 

DIY one-piece bathing suit

This is what your DIY swimsuit should look like so far. 

Sewing the swimsuit lining and elastic

3. Sew the lining and elastic into the swimsuit

Take your lining piece and flip it right sides out. Then, insert it into the main fabric piece and line the seams. In the end, both fabric pieces’ right sides should face each other. 

How to sew a one-piece swimsuit

Now, go ahead and sew the leg hole layers. You should be sewing through two layers for each side. 

Sewing the elastic on the seams

On the same seam, sew the elastic, slightly stretching it as you stitch along the seam. 

DIY swimsuit with bow tie

This next step is crucial - do not skip it!

Lining up the swimsuit

4. Line up the swimsuit

Take your swimsuit to the right side, then take the entire swimsuit in through the front crotch piece. Straighten up the suit and line it up correctly. It should be one big chunk. 

DIY swimsuit tutorial

Find the bottom portion of the front piece. You’ll see the lining piece is on the bottom and the print piece is on top. 

Easy DIY swimsuit

Now, sandwich it to match the right sides together. 

How to sew a one-piece bathing suit

Pull through the middle hole until you see more open seams. This will give you access to the back, where you can sew another seam. 

DIY bathing suit

It should look like this.

Sewing a bathing suit

5. Sew the seams

Line the seams and sew this section. 

Cute DIY swimsuit

The only seams left open should be on both the left and right parts of the top. Stitch these seams, too. 

Sewing the elastic onto the top

6. Sew the elastic on the top

Now, sew elastic to the top edge and the bottom of the bow-tie part. 

Sewing the straps of the swimsuit

7. Sew the straps of swimsuit

Fold the straps in half lengthwise and sew along the edge. Then, sew your elastic along the seam, too. 

DIY swimsuit straps

Turn your straps right sides out, and this is what they should look like. 

Attaching the straps to the swimsuit

8. Attach the straps to the swimsuit

Feed the straps through the strap openings by inserting them through the crotch. 

Sewing the swimsuit straps

Each strap edge should be inside each strap opening. Go ahead and sew the openings closed. 

Attaching the straps to the swimsuit back

To attach the straps to the back, seam rip two holes. You’ll need about a 1.5-inch section for the strap. Fold the strap and insert it into the hole. 

Adding strap adjusters

Optional: you can use strap adjusters, too. Attach the circular piece before you sew the back straps. 

Stitching the crotch

9. Stitch the crotch area

Align the crotch seams, then stitch them right sides together. Leave a tiny inch-wide hole so that you can turn the whole swimsuit inside out. 

Turning the swimsuit right side out

Turn the bow-tie one piece right side out through the gap. 

Threading the swimsuit straps

10. Finishing touches

Now for the finishing touches! Thread the straps through the loops, tie the bow tie, and manually sew the small gap by the crotch area. 

Cute DIY swimsuit with bow-tie front

Here’s the result! What do you think of this bow-tie DIY swimsuit? I love it, and it’s seriously my go-to swimsuit, especially on those off-days where I feel bloated or want to cover up my belly. 

I hope you enjoyed this tutorial on how to make a DIY swimsuit! Thank you for tuning in, and good luck. 

Suggested materials:
  • Swimwear fabric
  • Elastic
  • Cutter
See all materials

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