Here are some AC tips I've collected over the years. People who've played for a while already know these, but they might benifit a beginner. Also feel free to contact me if you have a tip to add.
Corpse Decay
When you die and you leave a corpse, you have a limited amount of time to retrieve it, before
it and the items in it disappear. The calculation is easy:
Your-level * 5 minutes = Time to decay in minutes
OR a minimum of 1 hour, whichever is greater.
So at level 10, 10 * 5 = 50 minutes. However, this is less than 60 minutes, so you have 60 minutes.
At level 12, it comes out even at 60 minutes. At every level higher, it is your-level*5.
Quick Healing Tip
Select a heal kit in your inventory. Click and hold, drag the icon to Slot 1 on your shortcut bar (below the inventory).
Select your main inventory pack on the upper right of your character's paper doll. Click and drag the icon to Slot 2.
To heal quickly, hit keys "1...2". Also, you are more likely to succeed in "peace" mode, but also more likely to take melee damage.
Luring a monster - for melee characters
If you are a sword, axe, etc. character, you can still lure a monster from a distance. Ask a fletcher to make you some Throwing Spikes with no wield requirement. You can throw them from a distance. Or if you are out in the field, pick up a pitcher, bowl, or any item that can be thrown and chuck that at your foe. You can find those on monster corpses. Remember you will probably miss because you aren't skilled in Throwing Weapons, but the monster should come running to you.
Pea soup - Make easy money
You can make easy money by picking up Scarab Peas from monster bodies. They are very light and return a good value when sold to an Arch Mage NPC.