Of course I've just started and you guys are more experienced but I always was under the assumption that you should speak to as many woman as you can in the place/setting (would also portray good social skills). If you are going to set number as a frame I think you should only do that when talking about venues and then you can state time and approx. number of approaches. i.e. go into 5 nightclubs, approach 6 girls and spend 20 mins with each.
As a newbie I think its of major importance to set yourself goals; it gives you something to aim for and accomplish. However, you should be open to the changing environment i.e. how I experience with a Canadian girl that we both just 'clicked' amazingly and I ended up spending most of the trip with her; which of course wasn't the initial plan, but do I regret it?... no.

Also to partly go back to the main question, I think that you shouldn't feel just confined to your own city, go out and explore a little. Sarge on holiday, whatever. I travelled 400 miles to London and ended up meeting that Canadian girl and I'm going to Romania later this year as well as Spain and of course around the UK; opportunities are endless if you make some effort.


**side note**
I've always found that once I've been talking to a set for 5 minutes I will ask something on the lines of "describe yourself in 2 words" ... make a comment about 1 of her 2 words and then say yours. It's a nice transition into a personality test for later on (if you use personality tests that is).