Here’s part of my Lightroom workflow:

1. Import. Rename during import to YYYMMDD–<old filename> (e.g. file MVWX1234.CR2 gets renamed to “20150129–MVWX1234.CR2”).
2. Rate pictures 1-5 stars, where 1=technically bad, 2=technically OK but not inspiring, 3=good to be shown to client; 4=one of the best in shoot; 5=portfolio photo.
3. Set filter to “3 and above only”.
4. Out of these, now decide which ones to actually use by flagging (“P, or “pick”).
5. Set filter to “flagged only”.
6. Edit them. Mark green (8) when done.
7. Set filter to greens only.
8. Export as required.

As you see, I create a funnel. As in “1000 images gets made into 850 “3+” images, and eventually to 600 picks”. It’s all about efficiency.