What you will need:
- Jumper/Onsie that looks like it's too short for the child (this one is size 24 months, but was wide, and I'm making it for my 3 1/2 year old)
- Quilting ruler- clear, 6 x 24 inches, roughly
- Rotary cutter or Scissors
- Coordinating thread
- Marker or chalk pencil
- Double needle for sewing machine (single needle instructions in parenthesis)
- Sewing machine, pins, etc.
Start off by laying the garment down, making sure that all the seams are flat, and the front and back are aligned. Place your ruler as close to the seams from the button bands as possible, making sure to square the ruler with the sides of your garment. Either use the rotary cutter and cut the bottom part off, or mark a straight line and cut with scissors.
**Side note: I like to buy jumpers with stripes, as long as the side seams are matched up (like below), then all you have to do is follow the stripe all the way around when you cut without even having to measure or draw a line.**
Next, fold the bottom of the garment-now a shirt :)- up 1/4 inch, and again 1/4 inch. This makes sure that the raw edge of the fabric is securely sewn under. And, pin. With stretchy t-shirt material, I like to pin a lot so that you are not trying to re-adjust while you are sewing, that will give you a wavy finished edge, not so pretty.
After you pin, you thread your double needles with the coordinating thread, and sew with the right side of the fabric facing up. (If using a single needle, I recommend sewing it with the wrong side facing upwards, and threading the bobbin with the coordinating thread). I like to use white thread as the thread that will not be seen, since I have tons of white and much much less of colors.
Ta-Da, you're done!