ALL HAIRDRESSERS‼️

i’m booking an appointment to get my thick hair cut about 3 inches to above my shoulders and when i cut it short, it’s always bulky and triangle shaped since it’s thick. i would like a straight across cut without layers, but is there any way to thin out my hair without layers? i know i should ask my hairdresser haha i’m just trying to get as much info as i can before.