Well the main offenders and the backbone of any competitive Eldar list are scatterbikes and Wraithknights followed closely by Warpspiders.
Those three things can be accompanied by formations or units that fill a gap in your playstyle.
Bikes. I field bikes in units of three all armed with scatlasers. On lower point games you need 3 units or 9 bikes and in bigger games 5-6 units. The more comfortable you get with your list and eldar as a whole you will be able to do with less bikes.
Wraithknights. If you field one then usually two wraithcannons will do the job and if you field two then one is ranged and one is melee. People can and they will ignore a single Wraithknight, especially if they field
MSU, but they can't do so with two. They should be used as agressively as possible since they act as a huge fire magnet.
Warpspiders. Those buggers are extremely mobile and they can wreck havoc with their weapons. Problem is you need to field more than one squad for them to be effective and be really careful since their weapons are close ranged risking an incoming assault. People know that the way to deal with them is to assault them so they avoid shooting them before assault. If you manage them correctly they are sick.
Regarding
HQ I tend to favor a Farseer always on bike or an Autarch on bike.
Now for heavy support consider two options. Falcons and D cannon platforms. The first is a mobile gunship with quite some firepower and the second is a dirty cheap D weapon that creates a no go zone and huge problems in your opponent advance against you.
Finally one forgeworld unit you need to get your hands on is the Hornet. Hornets are upgraded Vipers with 11 armor scout, acute sences, a special ability that allows them to snap shot after moving flat out and two pulse lasers! They cost one point less than a unit of 3 scat bikes and they deliver sooo much. Get two or even better three

You will use them no matter how many you have.
The above mentioned units will lead to and
TAC army around 1500 to 1850 points.
After that you can look to some flyers. Both of them are very effective and even stronger in formation.