In what ways can I "dodge" attacks?

It's clear that mobility is a huge part of combat in GW2. Obviously capital-D "Dodging" (i.e. double-tapping a movement key) allows you to avoid damage. Are there any other ways to avoid incoming attacks?

1. Strafing? - i.e. holding a movement key. You can clearly still be hit while strafing. Does your chance of avoidance go up?
2. Entering stealth? When an enemy attack has been fired, but you stealth before it reaches you, does this have any effect on the chance for that attack to land?
3. Shadow-stepping? Again, if you activate it while an attack is "in transit" toward you, does it affect the chance to hit?
4. Any other ways to dodge?

So here's the dirty little secret of Guild Wars 2 - targeting enemies is mostly a formality. The majority of your attacks work equally well with or without a target.

What this means in practice, is that whether or not you're being targeted is irrelevant. Are you in the path of the projectile, standing in the fire, or within the weapon attack cone of the mob? (Hint: If the Ogre raises his hands up, get out from in front of him!)

Which brings us to how to dodge.

Avoidance

Strafing is only effective on non-homing projectiles. Some home, some do not. Off the top of my head, the Guardian skill "Orb of Light" does not home, and can be dodged via strafing, while their "Ray of Judgement" Skill does, and cannot. Most mobs, however, can always be dodged by strafing.

Shadow-stepping technically falls into this category, as it is (usually) just a simple displacement. Most of the time, getting out of the path of the arrow will, in fact, dodge the arrow.

Line of Sight

Entering stealth does not inherently protect you from fired attacks, unless the same skill that granted stealth also granted you evade. (More on that a little below) If you're standing in front of the ogre, the ogre will still hit you, even if he can't see you.

For projectiles, you have another option; simply stand behind something. Projectiles which must pass through part of the world to get to you (such as the corner of a mountain, or particularly thick trees) will show up "Obstructed", and deal no damage.

Dodge Rolls

Dodge Rolls (by default, bound to double-tapping one of the movement keys) allow you to evade otherwise "Homing" projectiles. You'll still be "hit", but instead of damage or conditions, the message "Evaded" will pop up. You can even dodge through damaging zones this way, and not take any damage.

You may notice that some skills grant "Evasion", such as the Ranger's Shortbow 3. Abilities that grant "Evasion" are exactly like performing a dodge roll in terms of avoiding damage (though they will not consume endurance nor trigger dodge roll specific traits). Usually, they are accompanied by movement in a specific direction, though this is not always backwards.

Skill-Based

There are also a couple of skills that let you "Block" attacks, negating any damage or applied conditions. These skills often have additional effects that trigger (or can be triggered) if the block is not consumed. Additionally, the Guardian Buff, Aegis, allows you to block one attack. Some abilities refer to "Absorb", which is the same as block.

Projectiles also have a special counter -- certain skills can "reflect" them. This is about what it sounds like, with attacks being returned to their source.

Finally, there are a few skills that grant flat out "Immunity", such as the Elementalist's "Obsidian Skin". These will prevent damage and conditions, but will not move you. The Mesmer additionally has the "Distortion" buff which is identical, except for the name.

Conditional Defense

Lastly, there are a couple of conditions that can prevent damage. Blindness causes the next outgoing attack to miss (though it has reduced efficacy on bosses).

The other potential conditions are Daze and Stun. Daze interrupts all spells and attacks and locks them out for 3 seconds, while Stun interrupts and prevents all actions, including movement (though it's a little harder to get access to). A necromancer's fear can serve as an interrupt also.

There's not much to add that Raven Dreamer's great answer (+1) doesn't already cover, but I did want to add two small points just for clarification that may be useful to some:

1) The trick to avoid being hit by strafing is to change your movement pattern. When mobs launch projectiles (be they "physical" like arrows or "magical" in nature), they will aim for where you will be if you continue moving as you are. So, if you're continually strafing to the right, mobs will anticipate that and aim for a spot off to your right, and if you continue strafing to the right, it will hit you. That's not the same as a homing projectile that will change its movement based on yours. After they fire, if you stand still or move in another direction, the likelihood of the projectile missing will increase, depending on the distance between you and the "shooter" (obviously the best way to avoid being hit in this example is to strafe left immediately after they fire) and the speed of the projectile. Hence this is much more effective when you're out of melee range (if you're in melee range, in a one-on-one situation, always try to get behind the other guy or at least flank him). Like Mr Miyagi said, "Best way to avoid punch: no be there."

2) If you're going for the Daily "Dodger" achievement, the only type of dodging that counts towards that is if you use your dodge key (V by default, or double-tapping a direction key if you haven't disabled that in the settings). You will see a white "Evaded!" text when successful. Causing opponents to miss due to other factors (strafing, obstacles, blocking, blindness, etc.) will not affect your dodge count. Also, jumping will not help you to avoid being hit. (Another tip: trying to do daily dodger with a ranger can be frustrating as mobs will typically target your pet instead of you, and you often don't get credit for dodging if you weren't targeted. Stow your pet and don't get hit at all, or wait for the pet to die, or use a different character.)