Should I put a check/cash in the mail envelope with the template and instructions (by Erin) ?

Hi Felya,
Please do not send cash in the mail. You can send a check or we can invoice you via Paypal when your order arrives and you can put it on any major credit card.
Regards,
John

Alright I'm going to send in my template and order instructions made for me personally by Erin. I think you have my hair sample on file but she wrote the number just in case. How does the invoicing work?