Artificer tactics

Ranged tactics
You are bringing solid crossbow DPS into quests. Try stay in close range in order to benefit from increased damage via Point Blank Shot. Improve your burst DPS with Endless Fusillade and/or runearm blasts. When partying with melee characters, try not to kite monsters away from their melee range, they hate that.

Dogs
Your iron doggies are a useful asset throughout your journey to level 25. However, note that dogs are stupid and in some quests (especially end game/epics) they are often a liability (e.g. running off causing unwanted aggro). Please check with your party before calling your dog in a quest you are not familiar with.

End game raid tactics
As suggested by Shade in a forum thread, artificers are the ultimate scroll healers, able to cast heal scrolls at caster level 15 with +75 % effectiveness, for a total of 262 HP (before Healing Amplification).