Wash less, wash delicately
The truth is the more you wash a cotton garment, the faster it wears out. Wash your garment delicately by hand or in the most gentle machine cycle. It does not need to be in water for more than 15 minutes. Always wash whites with whites and darks with darks.
Easy on the detergents
Chemicals are what they are. While they clean a garment, they also take away the good stuff. Use minimal detergent and no bleach. Avoid putting detergent directly on the fabric, that can leave spots. Dry cleaning is extreme, your knit elements clothing does not need that.
Hand dry
Those spinning and drying machines are super harsh on good cotton. Hang or flat dry your tee. Avoid exposure to harsh sunlight, that can cause the colour to fade.
Correct grooming
Iron on hot while the tee is still damp. The neck rib is the most delicate part of the tee; iron carefully without stretching. Use a lint roller on solid tees so that they continue to look new.