The first thing to realize is that you definitely don't want to rank to hero as quickly as possible, because you'll be substantially if you get there without some key spells in each path.

The most key of those spells are your shields, so you should rank to 38? ASAP. You can, of course PK along the way, if you want, by utilizing stealth, your wide array of spells that hit vulns and getting people when they're not paying attention.

But, you really want to get to shields, especially if warriors are giving you fits.

A really important thing to do is to find a place, very out of the way, where you can spam. This is not your guild, this is not your cabal, this is not any place that has one or more of the following characteristics.

1. Nobody ever goes there. Yes, there are areas in the game that pretty much no one goes to. I spammed most of my spells up in one area (7 path elf) and no one ever disturbed me.

2. It's mazey enough that if someone enters the area they won't be able to find you quicky.

3. Your enemies can't get to. Make friends with people with detects and even if there's 3 Fire Giant RBWs in range, you can go to Arial City without a hint of fear.

4. There are mobs that will attack your enemies, but leave you alone. Know where the mobs attack evils, paladins, whatever, and if those are who you're dealing with, go there. This is less effective at hero, but there are places where mobs will outright kill certain lowbies two steps into the area, but you can walk around unmolested.

There are probably a dozen threads with tips for spamming, so I'm not gonna repeat them here, but TOME TOME TOME.

Get DA ASAP.

Learn which shields protect against what. Some minor shields have cool effects that are not immediately evident, so learn what to prioritize. Certain major shields protect from more than one thing.

FAST DESHIELD IS A MUST HAVE EDGE!

I found that the biggest thing that prevented me from getting PKs was not my low HP, but rather that I had sooooo many options that I'd be foolish and change tactics mid-fight. While that's a great option to have for when things aren't going your way, your best bet is to assess who your opponent is, come up with a plan and stick to it.

Just as Kot; Kans; Axe, should be your (imo) start to almost every assassin vs. warrior fight, come up with a plan for each race class and you should see much success.

Good luck. It's fun if you have the patience.