How can I set up a simple sequential numbering system so that for instance I have a custom name followed by a number. i.e. I import 5 images: London 1 up to London 5. Then the next time I go to import the system automatically starts at: London 6?
you can set up the Sequence you want and then create a Preset for it.
This way you can use that Preset for each import in Lightroom.
Refer Image Sequencing Options — Lightroom Secrets
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