All you‘re gonna need is a sewing machine, jersey fabric, matching thread, pins and scissors.
To begin you must be exceptionally well known in how to cut sleeves.
Once the sleeves are made, cut a rectangle in your fabric, mine is 40 “x 48” (however I’m tall). Measure 12 “from the top edge (this part is the neck cardigan) to stamp the upper connection of the sleeves.
Fold the rectangle in half and measure 10 “on each one side (aggregate 20”) this part is the back of the cardigan. Make gaps for the sleeves.
The estimations showed are mine, its best to take as reference the measure of one of your shirts.
Fixed sleeves inside each hole with pins and sew. That’s it!
It’s super easy to do.
***DIY source: www.ohohblog.com