All the basic advice on choosing and using pheros effectively is contained in these two threads:
And a persona; tip on application from me - Don’t overthink it and get bogged down in this spot over that. So long as it has access to the air and a good blood flow to promote diffusion, all is good. Also, don’t apply none or nols to hair as they bind and can get stinky and keep alcohol and oil app points apart as this will wreck diffusion.
Otherwise, have fun experementing and a bit more info along the lines of this thread will help us offer advice and get you your GC to get started with: