How to Make Your Own Swimsuit With a Sexy Cutout & Keyhole Design

Tools and materials:

• 1 yard of swimwear fabric (2 different prints)
• ¼-inch swimwear elastic
• Loop turner
• Seam ripper
• Rotary cutter or scissors
• Sewing machine
• Serger (optional)
• Elastic foot (optional)
• Matching thread
• 2 cord ends (optional)
• Clips
• Talia one-piece swimsuit pattern

1. Cut out the pattern

Cut two of each pattern piece. If you're doing a reversible swimsuit, as I am in this tutorial, you can cut the pattern in the two different fabric prints.

I get a lot of questions on whether to cut on the fold or assemble the whole pattern and cut it as a whole? I often cut on the fold because I have a small workspace.

However, I think for this pattern, which has a lot of curves, cutting it as a whole works better. Sometimes, when cutting on the fold, the fabric can slide a little and make everything asymmetrical.

Next, cut two strap pieces from one fabric. The measurements for these straps are included in the pattern. 

2. Sew the DIY swimsuit

Match fronts with fronts and back with backs, right sides together. When you sew the pieces together, attach elastic to the leg holes, inner curved side seams, and the top edges (you can see how I do this later).

When sewing the neckline area, leave a ¼-inch open on the top corners on either side. This is where you’ll insert your straps. 

For the back piece, sew and attach elastic to the leg holes and the whole top edge. 

Fold the straps over lengthwise, and sew along the raw edges and attach elastic. 

Here, I’m using a 4-thread overlock stitch on my serger. You can use a normal zigzag stitch if you don’t have a serger.

For more tips on sewing with swimwear elastic, you can see my video on All About Swimwear Elastic: Most Common Questions & Before You Sew.

I’m using an elastic foot in this video; it makes sewing elastic so much easier. I also have another video on Elastic Foot for Swimwear: How-To, Tips, and Problem Solving, if you need more information.

3. Insert the straps

Take your loop turner and turn your straps to the right side. 

Remember those gaps we left at the top? Now it's time to insert the straps there. Insert the straps into the openings, then pin and sew them in place with a straight stitch on your regular sewing machine.

If you're unsure, watch the video at 3:20 to see exactly where and how to insert the straps.

Now, trim any excess. 

Tuck in the straps. We want them to be completely inside the front piece.

4. Close the bust area

Sew one of the open ends of the bust area closed with a serger or zigzag stitch.

For the other side, leave a 1-2inch hole open. You’ll be using this hole to take the DIY swimsuit to the right side later, so make sure that it's big enough for that.

5. Attach the back piece

Turn the back piece right sides out and insert it inside the front piece. Start moving the back piece until you can align it at the sides and the gusset. Watch the video from 4:03 to see how to do this.

Pin these down and then sew across to secure. Use a straight stitch for the step, and trim off the excess afterward. 

6. Make a strap channel

Before we take the swimsuit to the right side, we'll be making some strap channels.

Since this style is reversible, I decided to make these channels from the inside. To do this, seam rip room for a strap channel right next to the outer edge of the bust pieces’ end sections. 

Go over the surrounding seams with either a serger or a zigzag stitch. This will make sure the seams don’t come apart. 

7. Turn right sides out

Remember the hole that you left open? Use that to turn the whole swimsuit to the right side. 

Finish that hole with either a topstitch or zigzag stitch, or you could do an invisible stitch by hand.

Using your loop turner, bring the straps through the strap channels you made. Be sure to thread the opposite strap, as this style has a criss-cross design. Watch the video from 5:20 to see how it's done.

Next, do a straight stitch right outside of your strap channel. 

8 Add the cord ends (optional)

Finally, attach your cord ends to each end of the strap. Put your cord end on your loop turner, thread the strap through, tie a tight knot, and trim the excess. 

Here's the final result. As you can see, there's some slight asymmetry around the bust due to the fact I cut the pattern pieces on the fold and wasn't paying enough attention when sewing the seams, but it's ok.

How to make your own swimsuit

That completes the tutorial on how to make your own swimsuit! What do you think of this sexy DIY swimsuit? This is such a hot style, it's ridiculous!

Thanks for joining me on this DIY one-piece swimsuit tutorial. Let me know your comments in the section below.