A simple workflow:
- Look at all your photos as small thumbnails
- Flag or select/pick/favorite your favorite photos based on small thumbnails
- If you see a photo which interests you when you’re looking at them as contact sheets (small thumbnails), *THEN* inspect the photos full-screen
- Choose all your favorited photos, and export them to Dropbox.
I say just use Apple Photos. The simpler software, compared with Adobe Lightroom. Also, better sync with iCloud between all your Apple devices.