If you can afford it, a track day or an advanced driving day would be best - I think TelfordMike and some others from here went on one and found it seriously enlightening (although very harsh on their cars!). Worth noting though that organisers of track days generally dont like it if they have to stop the event to go and rescue you from a gravel trap, so maybe dont go overboard on the experimenting eh?
To be honest (and this is something Im not proud of) Ive driven much closer to the limits of my car on public roads than Ive ever managed on the track: Not intentionally BTW, but sometimes you just go way too fast into a corner, lift off the accelerator causing mega-oversteer (because youre bricking it and instinctively do it!
) grab a bit of opposite lock, tyres howling and appear at the other side of the corner thinking "How the F*CK did I get away with that?" - I still dont think I can reliably find the limit at any desired opportunity - its more of an accident - but Ive found it one or two times, and in the instant afterwards you just grin, and grin, and grin... and replace your underwear...
So with my head - track days / drving days... With my heart - err... road, but well away from anything and everything that you could hurt, with the exception of yourself (sorry)
Hope I dont get too slated for saying that, but Im at least being honest, and I dont go out with the intention to speed or drive dangerously.