How to make a tie-dyed t-shirt
From Tie-dye Wiki
 Materials and Supplies
If you want to try tie-dyeing a shirt, you will need the following materials:
- 100% Cotton T-shirt
- Fiber-reactive dyes
- Soda Ash
- Squirt Bottles
- Dust mask
- Apron or old clothes
- Rubber bands and/or string
- Measuring Spoons, Cups
- Containers for Mixing and Mixing Tools
The following items are optional:
 Prepare the Shirt
Before tie-dyeing your shirt, it should be scoured or washed with hot water to remove any sizing that may keep the dye from adhering to the shirt.
 Mix the Dye
Next, you will need to mix the dyes. You can either mix the dye in water or chemical water. Fiber reactive dye will dissolve more easily in warm water 95-110 degrees. When handling dyes, you should be very careful to avoid spills. You should also wear gloves and a dustmask. Please review Dyeing Safety. Most sources recommend mixing 2 tsp of dye to 1 cup of water. Consult Procion Dye Concentrations for further discussion. Mix the dye thoroughly. Guidelines for Mixing Dyes Pour the mixed dye into squirt bottles.
 Fold and Soak the Shirt
You also need to fold the shirt. Some easy common folds are the accordion fold, spiral, and Scrunch or Chaos. Once you have folded the shirts, soda soak them in a solution of 1/4 cup of soda ash to one quart of water for 10-20 minutes. Try to squeeze out the excess solution without disturbing the folds. Some prefer to allow the shirt to dry out a bit over time--perhaps overnight.
 Apply the Dye
When you are ready, apply the dye to the fabric using the squirt bottles. How you apply the dye depends upon the the fold or folds you used. In the case of the a spiral fold, apply the different colors in wedges like pie slices. With a scrunch or chaos, you might apply the dye randomly starting with lighter colors and progressing to darker colors. Shirts tied with the accordion fold are generally dyed by applying dye to tied off sections. (Refer to specific folds for more guidance.) Make sure you get the dye gets into the inner layers by inserting the nozzle into the folds (unless you want a lot of white). Primary colors can also be blended on the fabric as the dye is applied to create secondary colors. For example, purple can be created by applying both red and blue dye to the same section of the shirt. Refer to Color for more information about color and for color recommendations.
 Cure, Rinse and Wash
Put the dyed shirt into a plastic bag and let it cure in a warm place (at least room temperature) at least 12 hours (refer to cure time). Remove the string or rubber bands and rinse out the dye starting with cool water at first, then rinse in hot water (some people put the shirts directly in the washing machine without initial rinsing). The shirts should be washed a couple of times before wearing--at least once in hot water. After that, most recommend washing with darks a few times before combining with regular laundry as a precaution.