70′s Angel Hair Style -1

What hairstyle is best for thick hair and do layers make it thicker or not?
My friend took a hairdressing course with school for a few weeks and she said layers make thick hair even thicker!! I thought it made it thinner? My hair is really thick and layered what hairstyle can I get to make it thinner? Oh and the hairdresser always uses thinning scissors and cuts loads off but by the next time I’ve washed it it’s like it never got thinned out at all. It’s so annoying what can I do?!
what IS the difference between thick hair and a thick head of hair?