i've made two types, some with elastic at the back so you can wear them and some with badge backs. i've made loads of these as they're really easy to make, the hardest bit is drawing out a good template.
Draw a template on paper and cut it out
Fold a section of felt over and pin the template to the felt. Then cut round it so you have two pieces of brown felt then remove the template.
if your a making it a moustache badge, attach a badge back and if you are making it into a moustache you can wear, attach the elastic. for the elastic tie a knot in the end and go through the back.
Now sew a bit up
when youve the top and one side of the bottom of the moustache fill it with stuffing.
sew up the rest of the moustache and youre done!
sorry if ive made this more complicated than it actually is - its actually really easy - but i hope the pictures help :)