This is an exerpt from an Article written by Kenny at Embroidery Library. Click on the picture above to go directly to the site for more information.
Hand-washing and air-drying are your gentlest options.
When machine washing embroidered clothing, turn the garments inside out to protect the embroidery from abrasion. When possible, avoid washing embroidered items with items that have metal hardware such as zippers.
To avoid shrinkage, wash the fabric as gently as possible, and air-dry if you can. Make sure to follow the fabric's care instructions.
If you're concerned about the thread color bleeding onto the fabric (or vice versa), wash gently in cold water. If you notice any bleeding when washing the fabric, rinse the item in cool water until the color is removed. Some say rayon thread is less colorfast than polyester thread, and deep red colors are most likely to bleed.
If pressing the embroidered item, either use a pressing cloth over the embroidery, or iron on the back. Don't let the iron touch the embroidery directly. Use dry heat and avoid the steam feature on your iron -- steam can cause the stabilizer to shrink up, creating a puckered look.
Keep in mind that all textiles show wear as they're washed and used. Your job is to help your embroidered creations age gracefully so that they'll bring joy and color into your life for years to come.