Modern Layout Collage Templates is a set of 16 different PSD templates with pre-made layouts for 3-8 images. There are separate sets for 6x4, 10x8 ad 5x7 aspect ratio.

Templates are scalable, vector based so you can resize them without penalty in terms of quality. The process of placing images into templates is automated using Photoshop actions.

Here is link to buy templates https://www.etsy.com/listing/669464035/modern-layout-collage-automated-psd.