In reply to The Lemming:
Yeah, I rate all mine after import to Lightroom.
1* - technically okay, publishable
2* - a decent shot, or a good shot with minor technical faults
3* - a very good shot with no technical faults
4* - a brilliant shot - only a few a year get this
5* - near perfect, can't think how they could be improved.
I've got less than ten 5* shots. I'm fairly harsh at scoring - maybe two-thirds of images get no stars.
I also add some basic keywords - for example climbing shots get crag, climber, route, rocktype, and everything gets filed by location.
I also colour code by subject - red for climbing, green for landscapes, blue for family etc.
When doing searches for clients I usually search with, e.g. 'red' and 'one star or higher' ticked (unless desperate).
On my laptop I've got a copy of the catalogue with smart previews for all the starred images. That means I can email previews/ mid-res images from wherever I am.
I don't typically delete no star shots as I find they can be invaluable for reference later.