Shaving backside of thigh

Okay, I know the title sounds weird but I can never seem to get the hair on the back of my thighs completely shaven off. I used to use women razors but, for me personally, they're don't get close enough to the skin. I've been using men's razors and recently signed up for the dollar shave club. I've also tried using Nair shave cream that you wipe off in the shower. I'm wondering do any other women have this issue as well? If so how the hell do you get the hair off lol. Thank you.