i had a 91 sorc that i let expire on hardcore. Its not really that hard when you get the hang of it....heres a few things to help....

1. Use pots whenever you lose health. you can always buy more, dont be cheap.
2. SAVE REJUVS
3. Do not Tele on Baal runs, especially in hell. Many have died just going down there and being ambushed.
4. DO NOT USE CHICKEN. Chicken takes 1-2 seconds before you actually leave. you will end up dead. If you do use chicken, set it pretty high so that it wont be a close call.
5. dont bot, its just not safe. Manual MF.
6. Get kick ass merc