Convert your desired image into a PSD mockup.
The PSD source file is the original mockup file with properly arranged and named layers. You can use smart layers to add your own designs or images without any limits.
All you need to do is open a coloured and labelled layer and paste your designs there and it will auto-update into the mockup. It's that easy!
You can buy and access the PSD source file any time in the future you wish to for $15.