Double herringbone stitch as trim for Viking underdress. This form of decoration was found on one of the Mammen textiles. See Carolyn-Priest Dorman's article on Viking Embroidery (article doesn't mention whether it's multi-colored or not, though)
A simple version of the Mammen vine scroll, and how to sew it freehand.
Instructions for doing opus anglicum, the English embroidery often used to decorate altar cloths and vestments. I understand it went into decline after the middle of the 14th century because so many of its practitioners died of the Black Plague.