Throughout my time playing the games, I've always built my first team in the following manner:
1) Get and train starter
2) Capture and train one pokemon found early in game
3) Capture and store everything else
4) Capture and train Legendary mascot
For instance, my Pearl team for the longest time was Infernape (starter), Luxray (caught early on), and Palkia (legendary). Also, my PC was over flowing with Pokemon I'd captured but never used, but I can't bring myself to release them; partially because I'll need them to fill up my B/W Dex and because they have some sentimental value to me, having been there so long.
Now for my White Version playthrough, I'm spicing things up a little. Instead of storing away every little pokemon I find so that it can sit around for only the initial purpose of it's Dex info, I'm going to capture a pokemon, either commit to training it or release it after a short while. The exception of course will be the legendaries; but that can be understood.
My main question for everyone is:
What is your playthrough style? / How will your BW style differ if at all?
-Do you cherish your starter and devote all your time to it?
-Do you train a wide array of pokemon and live by the old 'catch 'em all' tagline?
-Or do you own only the pokemon you train, caring naught about those little Dex entries?
(Examples just to get you started)