Like using hot water, there's no good reason to use harsh cleaning products on your clothes. Use a stain remover on spots but try to stay away from bleach all together. You don't have to use Woolite but use a mild detergent on your clothes.
This is the most important process you can do to preserve the life of your t-shirt. Turn the shirt inside out before placing it in the washing machine. Most often, when you take off the t-shirt after wearing, it just ends up inside out anyway, so just leave it that way when it goes in the wash. Third, turn your clothes inside out before you wash and dry them. Most people already do this with t-shirts and jeans, but all of your clothes will benefit from the inside out maneuver to prevent fading and to protect printing and embellishments
Always use cold water. There's really no reason to wash clothes in hot water unless you're a hospital or a hotel laundering sheets and towels. Cold water will get your clothes clean and it's certainly gentler on the fabric.A warm wash is not a hot wash. Hot water is NOT recommended for most t-shirts. Warm or tepid is best. In Australia we have a relatively warm climate, so our tap water is considered warm. Just using a cold wash cycle will be fine.
Never wash blacks, reds or any darks colours with your white t-shirts. It is best to wash all the similar colours together, as the dye will slowly release out of the t-shirt over time through washing. Wash only whites together. Wash reds together. And wash your darks together. You also want a load of wash to have similarly textured clothes to limit the amount of rubbing each item receives. Fabric rubbing is a quick way to create pills (even if you have a cloth shaver it's a pain to have to use it!), and custom printed items could crack and peel from too much friction. Just imagine rubbing a piece of sandpaper on your skin. That’s how a t-shirt feels when it’s washed with towels.
This will shrink most cotton t-shirts. Mostly, all styles recommend you do not tumble dry. Do not put your clothes in a hot dryer. We cannot stress enough this point about hot air and your clothes. Never set the dryer on its highest heat settings when you want to dry clothes (towels don't mind being cooked in the dryer!), and always remove them from the dryer before they are completely dry to hang up or lay out to finish drying. High heat is probably the worst enemy of custom printed apparel (and most clothes).
Just hang it out to dry, leave it inside out until it’s dry. Hang it out immediately, don’t leave it in the washing machine for an extended period of time. If you are hanging outside in the sun, make sure it’s inside out. The sun will bleach clothes and hanging inside out will protect the side that you wear (and the print) from sun damage.
Through this whole process the t- shirt is inside out. Leave it that way when you iron the t-shirt. Most prints should not be ironed on directly as this will damage the print. You can place a cloth or a piece of baking paper over the print, but it is recommended that you iron all prints inside out. A medium to hot iron is great for 100% cottons, but, polyester and poly/cotton blends should have a lower temperature.
Do not dry clean t-shirts; it’s not the right material