Hairblending for Hairstyles without OOT Expansion

desurekei

Hello!
I am very new so sorry for asking this question if it's stupid. My problem is that I want to apply OOT Hairblending to Hair without a specific oot expansion. OOT Hair is working normally and I understand how it works but I am too dumb to apply OOT to any other hair. Maybe some of you guys have an answer or any tipps. Thank you!