Flip your garment inside out before washing to protect the graphic from zippers, buckles and general abrasion in the wash. This will help maintain the artwork's integrity.
Using cold water in the wash process will slow any fading of the garment and protect the vibrancy of the print. It's also a better choice for the environment.
It takes more time, but the dryer is pretty hard on clothing. So when you remove your apparel from the washing machine, lay it flat or hang it on a drying rack. If you want that super soft feeling, throw your fully dry clothing in the dryer for a few minutes to fluff them up.
You just made a small change to make our planet better and keep your SML apparel looking nicer, longer. Garments that we take care of today become tomorrow's vintage. Cheers to that.