1. Take an ordinary pair of trousers. Make sure they're not too tight in the leg. I used a pair from UNI QLO. Or you could 'Upcycle' an old pair of trousers.
2. Take a ribbed jumper and decide how long you want the trouser cuff to be.
Once you've cut this lay onto leg of trousers lining up with the hem. If the trousers were a good length, mark with chalk where the ribbed cuff goes up to.
Then allow an extra 2-3ins trouser length for seam allowance and blousing and cut trouser leg here.
3. Put tube of ribbed sleeve right sides together over trouser leg.
Align seam of sleeve with inside leg seam.
Place under foot on sewing machine so you have the trouser fabric on the top.
Sew using a straight stitch and stetch the ribbing to fit the trouser leg as you sew.
Try on, if length and fit ok, zig zag edges of seam so they don't fray You have completed the 1st stage of your great new trousers. You can stop here or continue with the 2nd tutorial where you'll be applying the stetchy wide waistband