With High Elves, it's good to get into the fight as soon as possible. Only, allow them to support one another. Don't get surrounded! Elves are often small in number, especially compared to Mordor or Moria armies. Armies that have hordes of troops.
The twins, Glorfindel and Erestor are good heroes to have in an army. They are able to cut down troops and captains alike with ease. Only thing is to support them with troops: preferably spearman or archers to cover their flanks.
Elven archery is good, and rightly feared by lesser armies
.Use this to your advantage. Scare the troops to where you want with archery. With the right knowledge, you can control the opposing army to move where you want to some places, you could control the battle!
For example: With your dangerous Elven archery and you target some orcs, the opposing player may want to get his orcs clear of range of your archery as they will not want to lose their troops. With this, you can make them fall into a trap,
if you understand what I mean by this. It takes some practice, and I haven't completely mastered it myself. I suggest trying this if you know your army well.
This is all from my experience with elves, particularly the high elves. It may work the same for Lothlorien and Mirkwood, but I've used different techniques with my small Lothlorien army.
There's an article here about using a Rivendell army:
kb.php?a=215Hope all this helps