There's a number of different ways in which you can tie your t-shirt, but rule number 1 is to start with a loose-fitting t-shirt, because those are so much easier to knot.
The basic front knot
1. Make an O - shape with your thumb and index finger.
2. Pull the bottom of your t-shirt through the O, thereby pulling your t-shirt tight around your waist.
3. Push your thumb onto the fabric to keep it in place.
4. Loop the long end of the fabric around your index and middle fingers.
5. Pull the fabric through the loop.
6. Pull to tighten the knot.
1. Fold the back of your t-shirt in, then on both sides of the front hem pull your t-shirt tight so you have a bunch of fabric in both hands.
2. Fold both sides over each other.
3. Then knot them like you would your shoelaces.
4. Pull to tighten the knot.
Knot with an elastic band
1. Grab an elastic band or hair tie.
2. Make an O-shape with your thumb and index finger.
3. Pull the fabric through the O and pull the t-shirt tight around your waist.
4. Use your elastic band to tightly wrap around the tightest end of the fabric, and keep the knot in place.
Now you know a couple of different ways to tie a knot in your t-shirt, but feel free to play around with the placement of it! Try knotting the back of your t-shirt, or tying your t-shirt at the side, there are so many ways to turn a basic t-shirt into a fashion-forward top! Try it out for yourself!