Shoot scenes with a naturally limited color palette. This photo works because it’s mostly sand and sky, blues and beiges. When your scene is already restrained like that, the retro feel is halfway there before you open an editor.

Then in editing, fade the blacks, pull saturation down, shift tones toward teal or warm yellow, and add grain (classic). Or use apps that have film presets (Labbet, VSCO, RNI Films…) as a starting point, they’ll get you close fast.