So, let's start with something pretty basic! Deployment (concerning Eldar)!
With most armies, games COULD be won or lost in the deployment phase. With Eldar games ARE won and lost in the deployment phase. This also applies to reserves, as you will eventually have to deploy on the table. Remember, your supposed to be able to see into the future, so act like it. You should be planning turns in advance, for instance, when deploying, you should be thinking "where do i want this wave serpent by turn 3?" I'll agree this would be good if you played like this for other armies, but its more important to Eldar. With all the specialisation in the list, you need to get in the right place, at the right time, with the right units, and hope the enemy doesn't throw a spanner in the works.
Plan the game out roughly in your head, and i'm not talking about unit by unit precision moves, more generally "Those units" or "This flank" will move "Roughly to mid-board" or "Hang back then go for a turn 5 rush". When it comes to predicting enemy moves, simply assume the worst will happen. Those firedragons that just popped that Land Raider? Assume they will die, plan for it and still work out how to win. If they do not die, or even just one survives and holds, your at an advantage already.
Remember you do not have to deploy on objectives, its more preferable to ignore them and jump on then turn 5. If it looks like your not winning turns 1-4 it can prove very useful when you then go and claim/contest the majority of them in one turn, leaving your opponent (hopefully) spoilt for choice in what to do and not maximising his chances.
If you can force/trick an opponent to split his forces to counter your own you can quickly converge on one part of it, annihilating it in short order, with minimal losses.
The biggest mistake a player could make against Eldar is splitting up, as one of the things Eldar can still do exceptionally well is point at a unit and make it disappear (it helps when dooming the unit to shout "Doooooooom", along with jinxing the the enemies rolls by saying things like "you should be fine, anything but a 1 and your golden" or "Ld 10? you can't possibly fail!")
One thing Eldar can't do so well is get hit back, so its best to wipe units out one at time with concentrated firepower, which is where the enemy splitting up comes in =D They do the work for you as you can then casually take out the lone unit/units without getting blammed by the entire enemy force.
Which is where deployment comes in, you need to see/guess where the enemy will deploy, and deploy your own forces accordingly. Place your rock against his scissors and place your paper far, far away. As most missions are objective based it's best to go second, this also lets you see exactly where the majority of the enemy army is deploying in most cases.
Eldrad is extrememly useful when your going first with his divination, but as its a random amount of units moved, and the enemy should see it coming, its not as usefull against your regular opponents.
Another thing to point out is there is no shame in hiding. Is there a large LOS blocking piece of terrain? Use it to your advantage, your speed can help you get LOS around it but its perfectly acceptable to cower like a lost puppy to keep your units alive in that first turn.
And remember bait unit. This applies to later turns as well as deployment. If you can make it harder to kill whats important to your plans and present an easy kill for the opponent, they might just take it. I find alot of players simply shoot the closest or easiest to kill units they can see so you can use this to your advantage by setting up bait.
Anything you don't agree with or think i should add into V2.0?