I'd like some advice for designer who does vintage designs

Your best bet is to build mood boards/idea boards based on what aesthetics you like from each decade and use that as inspiration to move forward with your designs. You can do this on Pinterest, Behance and other sites. You can even build your own physically if that works better for you.

Look at fonts used, colour schemes, patterns, textures, style of photos, etc to give you an idea of how to incorporate that look into your designs.