By aiming Mystic Shot in brushes and watching your cooldowns while listening for the Mystic Shot hit sound, you can see if enemies are hiding in a brush.
Keep an eye on your Rising Spell Force stacks and whether they increase. This aspect allows you to check brush with Ezreal's other abilities as well.
If attacking a tower with an ally, you can use Essence Flux on them to boost their attack speed. Hitting the friendly champion will also increase the stacks and duration of your passive Rising Spell Force.
In the lane, Ezreal's early burst damage and poke is very high. Combine this with a lane partner or jungler's crowd control to get some kills.
Do not underestimate Essence Flux's damage, espeically with a bit of Ability Power. With some aim, AP Ezreal can easily harass and burst enemies down safely behind minions.
Remember that Arcane Shift can be used to jump terrain spots and walls in the jungle. It is your best escape mechanism.
Be careful using it offensively in a skirmish as people will know to focus you while it's on cooldown.
Take note of the surrounding area. If Ezreal is low on health and tries to Arcane Shift over a wall, the escape attempt will be pointless if the homing missile targets a jungle monster and pulls aggro.
Use Arcane Shift to help line up your other abilities, but avoid using it in situations that would leave you vulnerable.
Although Trueshot Barrage is a channeled ability, you cannot stop the channel with hard CC. The only way to prevent Ezreal from ulting mid-cast is by killing him.
Never forget that Trueshot Barrage is global and you may be able to snipe a enemy champion from all the way across the map if you have good aim. You can also use it to soften up a enemy that you are aiming to fight.
If you decide to snipe a fleeing enemy, make sure they don't have any sort of heal, shield or invulnerability.
Use Trueshot Barrage when the enemy has no vision of Ezreal, so they will be unable to warn their teammates.
Also note that Trueshot Barrage can be seen through the fog, so a wary opponent can watch for it and avoid it from a distance.
Trueshot Barrage has a channel time upfront and is easily dodged by skilled players. For this reason, it is often a good idea to use it to hit an entire team immediately after the battle starts, dealing significant total damage and granting multiple stacks of Rising Spell Force.
Trueshot Barrage is especially powerful in Dominion, delaying enemies' attempts to capture your towers and buying crucial time. Due to its relatively low cool down in conjunction with Mystic Shot, use it wisely and use it often.
Smart casting will give you a faster response time, allowing you to hit more abilities.
Last Whisper complements Ezreal for Mystic Shot and attack damage. While less-useful for regular auto-attack than The Black Cleaver, the armor penetration is the strongest against mid-high armor stacking champions, it is an amazing item against tougher enemies. Its low cost makes it an affordable purchase in the early-phase. However, it's not exactly suitable for ability power and/or hybrid builds as Youmuu's Ghostblade is.
The casting of Mystic Shot procs Sheen's damage buff, which is then applied when the shot hits the target, thus increasing its damage.
If you miss Mystic Shot, auto attack the enemy once before casting Mystic Shot again. Same applies for using other abilities before casting Mystic Shot, as not using the Sheen can decrease DPS considerably.
If using a primarily AP build, it is much better to go with Lich Bane than Trinity Force to improve this proc.
Within the preparation phase of Dominion in the early 1:20 minutes, Ezreal can start collecting Mana with Tear of the Goddess by keeping every ability on Cooldown. This can serve as a minor improvement for the early phases.
While the bonus Mana pool of Archangel's Staff and Manamune are the same, they compliment each other very well. Getting both requires a high level of farm though. Nevertheless, each item is very useful if quickly farmed and can be a fundamental part of most builds.
Ezreal cannot trade fairly during close combat and rely on poking as much as possible. Having a champ that can dash or blink towards him (ie Xin Zhao , Diana , Irelia ) would cost Ezreal his blink to run away from the team fight and be isolated from the defending allies causing his death.