Somehow I missed this post. Here are my thoughts:

1. Read all the help files for each class spell/skill/song/prayer. Know your enemy; know yourself.

2. Read logs of other people fighting. If you see something that conflicts with how you think things work then get someone to explain the discrepancy.

3. Play a lot and learn the layout of the areas of the game. The diku maps help some.

4. Learn what gear to aim for given the combo you're playing. You may not ever get it but you at least know what to greedily covet.

5. Figure out (mostly by asking in game) where to get common preps including what common preps are even available. Flight, protection vs. alignment, resist heat/cold/lightning/negative if you need it, resist mental, cure blindness, pass door.

6. Figure out how to amass gold as efficiently as possible. Unless someone spoon feeds you this info then you'll probably need to ask around in game. People are notoriously unwilling to share their gold sources in a public forum since it means they may get "fixed".

7. Keep various essentials in your inventory (not just in a container!) to prevent death. Return potion, multiple teleport potions, cure blindness, detect invis (if you need it) and enough gold to heal yourself. At hero you might want to add pills to heal and refresh yourself.

8. Don't participate in any fight you didn't start. If someone surprises you then get the heck out of there immediately.

9. Train yourself not to stack commands. That especially includes spamming "flee" ten times.

10. Get a client and learn how to create highlights and aliases. Create a basic set of aliases. For instance, "q" for "quaff return".

#1 and #2 mean you can at least formulate a reasonable strategy for beating someone.

#3 means you might be able to find someone to kill (or gear you want) and you won't be totally lost if/when you have to teleport away.

#4 should mean you will have at least passable gear, even if it's only "regear" quality.

#5 means you won't lack the basic preps most people use, so you're not hamstrung in that way.

#6-9 mean that when someone does "beat" you in a battle you don't actually end up dead every time; you make your escape and live to fight another day.