Creating PPC ads

I’ve got to produce PPC ad images for the new event campaign. There’s 48 different (but many similar) sizes, all in pixels (there’s about 4 with ratios instead, but the pixel ones are fixed).

I’m using Photoshop, and all the ads going to have same base items - background, logo .png, date of event, and possibly “Click here”/“Find out”

However, as far as I can gather I need to start afresh for each one - create new, enter the size, copy and paste in the new items, size accordingly.

Does anyone have any suggestions about how to create them more efficiently? Using the same canvas but resizing doesn’t work.

You don’t need a fresh start for each ad. No reason you can’t take an existing ad and modify it. This assumes you’re following best practices and using layered PSDs, live type, adjustment layers, smart objects, libraries, etc.