If you want to become good@pvp

do as much pvp as you can. PvM will give you the basics (which child does not know how to move a mouse in 1 direction and press [insert your TELE-Button here] -key to tele and to repeat the same shit for shooting....)
Nice for some1 who started Diablo2 yesterday perhaps, but thats all.
Find some gm duels, duel alot (2 hours a day is more than enough) and you will become better...