My 12 year old son made a coat of arms, shown below. We did a lot of research on-line, without much definitive direction. I suggested to my son that he divide the shield into fourths, with one set of opposite corners representing his father's surname and the other set of opposite corners representing my maiden name. I've heard that my husband's last name is Irish and means fisherman, so I suggested shamrocks and fish in whatever style my son deemed best, based on his research of looking at other coat of arms. My family name is German and extremely complicated. My dad told me that it was actually longer at one time and is now simplified. That is funny, because my maiden name was a never ending source of frustration because no one can spell it or pronounce it! I told my son to create his own symbols for the rest of the crest.
My son wanted to be Robin Hood and had strong ideas about the costume. He let me make his clothing and hat. He insisted on boots that we can't afford for rapidly growing feet, so he made the boots himself. I thought it would be impossible but here they are! (Future note: He later wore these with different military costumes (and here) and looked pretty good! Then he told one of the Colonial Williamsburg shoemakers how he made them and they said that is basically how they make some versions of boots too, then they got a pair to show him!)
He also insisted on a bow and arrow which he made. When we studied Texas history we had learned how the Native Americans of Northeast Texas were master craftsmen of bows because of the bois de arc wood. Their prized bows made them traders throughout the land. My son really wanted some bois de arc wood but I told him we couldn't source any from San Antonio. He settled on a certain twig from my crepe myrtle and created his own bow and arrow, which he is wearing.
I read in some Medieval Feast scripts that the participants collected food for the poor. I have no idea how historically accurate that is, but it is certainly a nice touch in memory of all the poor people Robin Hood tried to help. This is especially nice when done near Thanksgiving.