Here is an incredibly simple trifold mock-up template for use in Blender (a free 3D software you can download at: https://www.blender.org/download/).

You do not need any experience using Blender!

I've made a quick video showing you step by step how to make your mock-up in seconds:

The pamphlet used in the example is for my Liminal Horror module, The Chair.

SOME IMPORTANT NOTES:

• Be sure that the images you are using are the correct size for the template you're using. For example: if you are using the US Letter template, then your files need to be sized in the same ratio as an 8.5"x11" sheet (the actual size doesn't matter, but the aspect ratio must be the same!)
• Don't just crop to the cover for your exterior/cover image part of the template. Make sure it's the entire side of the sheet your cover will be printed on.
• THIS IS A TEMPLATE FOR MOCK-UPS ONLY! It is not a template for laying out a trifold pamphlet for print.
• Currently this is only for US Letter sized pamphlets, but I will be updating this soon with one for A4 size as well. Available in both US Letter and A4 now!

LICENSE

These mock-ups are free to use for any project or purpose, personal or commercial. Attribution is not required but greatly appreciated.