You're going to need:
An oversized t-shirt [hell a regular fitting tee will do fine!]
The t-shirt pattern you made!
Stretch lace/ribbon


I cut up one of the sideseams of the shirt and across the shoulders so I could open the shirt out.

Fold the shirt in half so you can see the print, making sure it's centered! Pin the front pattern to the shirt and cut out


Pin the sleeve pattern to the existing sleeve and cut it out. I used the hem on the original sleeve



Now trace around the back of your minidress pattern. I traced about 5cm under the armpit then ruled a line across.

The pattern piece is sideways, the shoulder is at the top left, the neckline on the left

Fold the back pattern piece of the mini dress at the line you made, then ad one cm and cut out. This is the lower back and majority of the back of the dress


No matter! I cut the remaining sections out of scraps and stitched them on

Pin the sleeves so the right sides are on the insides and stitch


It should look like this!


Stitch down the centre back with the longest stitch [or the gathering stitch if you have it on your machine]. Gently pull the threads before clipping them, helping the fabric with your fingers to gather up.


Stitch the back to the front at the shoulders


It should look like this [inside out]



Pin the rest of side seams of the front to the back + Stitch!

Pin the sleeves to the armholes and stitch [One day very soon I'll put up a  sleeve attaching tutorial!]


Make a floppy bow from the scraps! I used the side pieces I had cut off




 I safety pinned the floppy bow over the gathered piece of the back