Add your design easily: Just drag your design to the opened SMART object and save changes. Your design is already there! Individual smart objects in the SMARTS folder allow you to add design to every part.
Please check out my Sports and Apparel Mockups:
T-Shirts Mockups || Soccer Jerseys || Shorts || Hoodies & Sweatshirts
eSports Jerseys || Hockey Jerseys & Uniforms || Baseball & Softball
Jackets & Outerwear || Hooded T-shirts || Varsity & Bomber Jackets
Leggings || Sports Kits || Pants || Sleeveless Shirts || T-Shirts On Hanger
Long Sleeve T-Shirt || Dresses ||Bags || Soccer Balls || Wall Tapestries
Face Masks & Respirators
You can find all my mockups here: Sports and Apparel Mockups Collection Sample design is not included in the download file.