Hey guys. So I've been wearing a topper for a while now but have always had difficulty cutting the lace to match the bald area of my scalp. I could really use some advice to improve my technique.

I've attached a pic of my scalp - I'm a diffuse thinner and I've shaved the affected part of my hair. As you can see, I have decently thick side and back hair. I do leave some front hairline and attach just behind it because I feel it provides a more realistic look.

The trouble I'm having is cutting the lace to the shape of the bald area - I can never get it perfectly matched. My attachment preference is to put tape on the perimeter of the lace and then place it down on my head. Because I'm unable to cut the lace to the shape of the bald area, I always end up inadvertently taping my unit down on top of some side/back hair, which results in a poor attachment.

I'd appreciate any input on how to cut the lace more accurately or any other advice you can offer. Thanks.