A lot of the game involves running from Point A to Point B, and can often be done while ignoring the enemies in the way. Movement speed boosts are crucial, and the rest of your party can handle combat, usually. You'll probably want to play a Monk (+10% speed per 3 levels) with a level of Cleric for the Travel (+10% speed, as Barbarian) and Plant (+10% speed outdoors, as Druid) domains. If you intend to perform the HP glitch, you'll likely need an odd-numbered Constitution score for your character (or you can use Elanee who has one naturally).

Tutorial

After the opening, you can skip the tutorial and go straight to Chapter 1. You'll immediately gain enough experience for level 3 (3000 xp).

Chapter 1

West Harbor

The 3 Duergar on the first floor of your home always have the same items (Club +1, Quarterstaff, Short Sword, Healer's Kit +1). You can just run past them, but Monks may want the quarterstaff to get 1.5x Str to damage instead of 1x Str from fists, and the club sells for ~600 gold.

If you can cast healing spells, you don't need to get the healing moss from the priest to heal the miltia (an option comes up in dialogue) (Only tested with Cleric).

If you skip past the trigger that gets Aimee killed, you can keep her for essentially the rest of the game. She's nigh-invulnerable for some time, too.

Smilge: "Ran away from all enemies, got the salve from the priest to heal wounded militiamen, and heals the one nearby (1/5). Went to the fence near the river and did the save/load trick to hop over it with Amie (the girl). PC uses diplomacy to convince a guy to fight for the militia (2/5). Bevil helps kill the enemies around the militia leader. Amie helps kill enemies around two militia, and talks to a nearby pig to teleport the PC to finish them off. Bevil talks to the militia leader ASAP, and Amie talks to the two militiamen she was helping ASAP (4/5). Either Amie or the PC talks to the closest wounded militiaman (5/5) then to the militia leader to start the waves of attackers. I found that ignoring Bevil's family was faster, but I can check again. Once the waves are dead, go to the swamp ruins."

Swamp Ruins

Weeping Willow Inn

You don't have to kill the bladelings and duergar inside. Just run out once Khelgar joins your party.

Fort Locke

Highcliffe appears on your map once you have Neeshka. If you save Galen, he appears to have the earliest Con-boosting item for the HP glitch (Boots of Hardiness +1, ~3000 gold).

Maiden's Glade

Just run past the animals.

You get Elanee here. If you have Galen's Boots of Hardiness, you can do the HP glitch on her with the Bear's Endurance spell.

Highcliffe

Highcliffe Castle Ruins

The zombies fighting Slaan disappear as soon as you open the castle door. Being friendly with Slaan and the lizardmen is obviously much faster than fighting through the lizardman lair.

The Shadow Priest here has an Amulet of Vitality +2 in case you don't want to rely on Bear's Endurance to use the HP glitch. Otherwise, you don't need to fight him at all.

Neverwinter Docks

Neverwinter Merchant Quarter

Old Owl Well

Bonegnasher Lair

The leader of the orcs initiates a conversation and then runs away. If you catch up to him and talk to him, he'll start a second conversation that normally wouldn't happen till you ran over a trigger further in the cave. When you run over the trigger, it skips ahead to the conversation as if you defeated him. Basically you skip fighting him. After that, ignore the human and exit the cave.

Eyegouger Lair

Neverwinter and Githyanki Hideout

Blacklake and Neverwinter Archives

Shandra's Farm Revisited

Sunken Flagon Fight

Ember

Githyanki Base

Chapter 2

Chapter 3