Cassia Leotard Tutorial Part 3: Adjustable Straps & That Dreamy Scrunch Bum Detail
You're SO close. Let's finish this beauty together.
Hey gorgeous! Welcome back to Part 3 of the Cassia Leotard tutorial series — and can I just say, if you've made it this far? You are absolutely killing it.
Parts 1 and 2 are done. Your fabric is cut, your lining is sorted, and you're starting to see this leotard come to life. That moment when a flat piece of fabric starts looking like an "actual garment"? Priceless 😭. There is nothing like it.
Today we're tackling two of my absolute favourite parts of the whole Cassia construction — the adjustable straps (because one size does NOT fit all, and we are done with leotards that dig into our shoulders) and that iconic scrunch bum detail that makes the Cassia so special.
Grab your coffee, get your machine warmed up, and let's do this.
What You'll Learn in Part 3
By the end of this tutorial you'll know how to:
✨ Make and attach fully adjustable straps: so your Cassia fits your body perfectly — whether you're long-torsoed, short-torsoed, or somewhere in between
✨ Position your straps: for the most flattering and comfortable placement for your unique shape
✨ Sew the scrunch bum detail: — that gorgeous ruched finish that makes everyone ask "wait, where did you GET that?"
These skills aren't just for the Cassia either. Once you've got adjustable straps down, you'll use this technique again and again across so many patterns. This is a proper skill upgrade, my friend.
Part 1: Making Your Adjustable Straps
Okay, let's talk straps — because this is where so many ready-to-wear leotards fall short. Fixed straps mean fixed fit, and that works for exactly nobody.
The Cassia uses a simple, clean adjustable strap construction that looks polished and professional, and gives you full control over your fit.
What You'll Need
- Your strap fabric pieces - Full measurements are in the pattern download
- Coordinating thread
- O rings / sliders (sometimes called swimwear rings and sliders)
- Bikini Clasp
The Cassia was designed to be worn, loved, and made again and again — in every colour, every print, every fabric you've been hoarding. (We all have the stash. No judgement.)
Ready to Go Deeper? Here's How I Can Help You
If you loved making the Cassia and you're hungry for more — I have something really special for you.
🎓 The Cassia Mini Course
Take everything from these tutorials and go further with the Cassia Mini Course — a step-by-step video course walking you through the entire Cassia construction with me by your side.
And right now, it comes with a FREE bonus: the Acacia pattern. That's two beautiful leotard patterns for the price of one course. The Acacia is the Cassia's sleek, elegant sister — you are going to love her.
Get the Cassia Mini Course + Free Acacia Pattern
Or — if you're ready to go ALL in on your leotard-making journey — the Leotard Wardrobe Vault is your new best friend.
Inside you'll find:
- 7 leotard patterns and full tutorials (and counting!)
- New patterns and tutorials added regularly — this collection keeps growing
- Everything you need to build a complete, gorgeous leotard wardrobe from scratch
This is the ultimate resource for anyone who is serious about sewing activewear that actually fits, feels incredible, and looks like it came from a boutique.
Join the Leotard Wardrobe Vault
Whichever path feels right for you — I am so honoured to be part of your sewing journey. You've got this. You've always had this.
Now go make another one. 🖤
Love,
Leonie
Missed the earlier parts? Catch up here: Part 1 | Part 2
Tag me in your finished Cassias — I want to see every single one!