I've had my 370Z for just over a year and a 350Z almost two years directly prior - I've still not gotten a smooth 1-2 gear shift 100% :P I also don't leave the house much since I work from home a lot
So not too much practice. But all the advice here I've tried myself and various combinations will work for your own personal driving style.
And yea, that *clunk* is so annoying, but it's just another thing you learn to live with. Only happens now and again for me