Thanks
The way I did it was:
1) Made some digital shapes in Illustrator.
2) Printed out the shapes and spayed-glued each one (seven in total) to a thin card-stock (I used a couple old file-folders).
3) I then cut out each shape with a ruler and sharp xacto knife.
4) I was left with seven individual digital shape "cards" - this lets you hold up a different pattern and spray without worry.
5) Taped off the veclro that was already on the helmet and sprayed a good base coat of Krylon tan.
6) First I sprayed a random layer of digital shapes in Krylon brown - then dusted over that with a light mist of Krylon tan.
7) Then I sprayed a second final layer of digital shapes in Krylon brown - then dusted over that as well with a light mist of Krylon tan.
8) After everything was dry, I removed the tape on the velcro and gave it a light mist of Krylon tan - then sprayed random digital shapes onto the velcro with Krylon tan.
I recommend to practice with your stencils first before using them on your helmet. I found it was best to hold the spray can a medium-to-far distance for the best results.
I have some tan adhesive velcro on order to replace the black velcro on the helmet now - but I am like how it turned out