A couple of peculiar things you may or may not know about the elementalist.
•Ring of earth blocks projectiles
•Frost aura stacks in duration
•Attuning to water will break aegis on nearby opponents, even though it has no effect on them whatsoever
•Shocking aura stuns the opponent when you are hit, and can therefore, much like retaliation, not be blocked or evaded. As such you can use it to interrupt pistol whip, blurred frenzy, or even shelter when standing in a guardian's symbol with shocking aura active. Even effects that do no damage will trigger the shocking aura stun. You can for example use it to interrupt a churning earth by standing in the crippling aoe.
•Churning earth's cripple pulse while channeling can be blinded or blocked. This can cause some surprising effects when your opponent attempts to blind you during the channel, as your cripple will consume the blind while your damage goes off unhindered
•You can activate magnetic leap long after the immobilize wears out. This is especially useful vs stealthed opponents. Waiting as long as possible and then leaping can completely deny the element of surprise from stealth.
•When you start channeling churning earth before your opponent enters stealth, your character model will face towards the stealthed opponent while channeling. This can also allow you to track someone in stealth, while giving you a much better chance to land a seemingly blind churning earth. I believe ( not entirely sure) the same is true for drake's breath and cone of cold if cast while standing still.
•Ring of fire can stack up to 25 seconds of burning if your opponent repeatedly enters and exits the field. That's 10,000 damage, so try to make good use of this skill. Blinking through the walls will still apply the burn!
•Glyph of elementals' water elemental uses an ability that will aoe heal for 6570, making it the single largest aoe heal in the game. Learning the animation can help you a great deal.
•Tempest defense will still pop if you get hit by cc with stability up.
•Stability is last in line to get ripped, so if you're up against a corrupt boon necro, try to have 6 boons up when casting ether renewal with stability.
•Magnetic grasp and phoenix are unblockable. EDIT: as is the water staff 4, Frozen ground. Thanks to the beautiful and elegant WoodenPotatoes.
•Ether renewal will go on full cooldown, even when you're interrupted before the spell has even pulsed once. Usually a spell will only go on full cooldown once it has at least granted part of its effect. Churning earth and shelter for example, will go on the standard ~4s cooldown if interrupted before the first cripple or before the block takes effect.
•Although Ride the lightning does aoe damage when it lands, it will do no damage at all if the target avoids it or if cast untargeted. If for example a mesmer traited with clone on dodge dodges at the last second, the clone will not be hit either.
•The evade on burning speed can allow you to safely pop marks and traps, but not cross line/ring of warding or unsteady ground.
•Auras acquired by combos will not be shared through powerful aura (flame leap or ice blast)
•You can change the orientation of Staff earth #4 by changing the direction your character is facing while casting the ability. By default the wall will appear perpendicular to the direction your character is facing, but by quickly turning your character while casting, you can pivot its orientation at will.
Let me know if i missed any!
EDIT: thought of one more, a rather big one.
•You can reduce the distance travelled by Burning speed by angling your camera as high as you can(picture trying to aim burning speed into the ground). This can be very useful when trying to hit someone in melee range. Note that this trick is only about 60% reliable.
EDIT: And another one
•Elementalist has access to stealth underwater by using earth 5 to create a smoke field, then water 5 for a leap finisher and water 3 for a blast finisher. (Area swiftness with air 5)
Edit: Thanks to /u/ErifEci
•Thunderclap, or the final hit of Lightning Hammer, ignores dredge's blind immunity. At least for non-champions.