Items needed: one sheet each of white, red, green, and brown felt; elastic cord; scissors; red newsboy hat; green newsboy hat (purchased here); sewing machine and thread; overalls, red and green shirts
Cut two "domes" out of the white felt. I held the felt up to the hat to gauge what size I would need to cut it, then I folded the felt in half and cut half the dome on the fold so the sides would be even. You could also do a circle instead of a dome if desired.
Cut an M out of the red felt and center it on the white felt. Sew it on to the white felt. I used red thread to blend in with the felt.
Cut an L out of the green felt and center it on the dome. Sew it on using green thread.
Next, pin the M onto the hat. Carefully sew it to the hat. I found that using lots of pins to hold the M in place helped.
Repeat the pinning and sewing with the L hat.
TaaDaa! The hard part of the costume is done!
Now we're ready for moustaches! Cut the moustaches from the brown felt. I measured my kids' faces to see how big of a moustache I'd need to cut. For my kids, I needed one approximately 3 inches long and 1 inch high. For Luigi, cut a moustache shaped like the one above.
Then poke holes on the sides and tie the elastic cord onto it.
Mario's moustache is slightly different than Luigi's as can be seen in the picture above.
Finally, get a plain green shirt, a plain red shirt (I got both at Target for $5 each) and some overalls. Throw in a Princess Peach and you have a Nintendo Halloween! These costumes have made their way into our dress up trunk and are still used a lot!