Stanlore
Super Freak
Yes this is the right procedure to follow in my opinion...
I found it easier to do it with the mask on. At least the mask is held and secure first. For me, after that i had fingers clinching both sides, and slowly slid it simultaneously.
With the before option, i had to focus on holding the mask, and holding the clips and turning the cat ears all at once. Too many things at the same time. I found it easier for me to do it with the mask on.. one less thing to focus on.