I have done prem clothes in the past. I never hoop any stretch material but rather hoop stabilizer and then use a spray adhesive. Turn the garment in side out and pin around the area you want the design. As somebody has already said. Do not leave your machine for a second. Good luck. Sarah.
You could try using this technique.
Be sure to use an iron on stabilizer before you begin so it doesn't stretch the fabric and distort the design or shirt
Try turning it inside out, Kitty and just pinning or basting the bit you need onto the hooped stabiliser. You'd have to guard it like a hawk to make sure the outer parts don't accidentally end up under the needle too. There is a gadget -called a Sock-It, I think, to help people do the edge of socks.
I hope this link will help you.
Thank you for the link, I tried that but I think my design & hoop must be too big. I'm working with a 4x4 hoop & a 000 singlet size :( a nightmare
I did like the template & stablizer advice on that site though... if only my garment was a tad bigger,, it might then work