Low defense only matters if you get hit.
The key to Wood Elves (or any Low-D force) is to not get hit. Simple, right?
Seriously though, this is actually pretty easy with Wood Elves, especially after the reduced effectiveness of bow fire.
Elf Spears are a key consideration with WE armies. When you are in a Fight you need to have multiple dice being cast to increase the odds of you winning. If you do get a tie then your high Fight value will be the next factor. Now any spear supported model is casting more dice but the WE Spears have another nice bonus. You can shield with them. Now your single WE alone can still roll two dice if needed (if he's alone, facing more enemies, for example). I have often used one or two WE w/ spear just shielding to hold back enemy in an area either as a delaying tactic or until help can arrive.
Max out your archery. Even under the new rules Elf Bows (stationary) can do some damage. You really need to thin the ranks of your opponent as much as you can before your lines clash. You're not going to shoot up so much that you can walk all over them but you want to pick proper targets (lowest Defense, support models, cavalry, etc.) and focus.
The Sentinel song that allows you to move an enemy that fails Courage is wonderful, especially against Trolls and similar low-C Monsters.
But it also works good for breaking up enemy formations a little.
Do NOT engage with typical tactics. You're not a shield wall force so don't play like one or be sucked into it. You want to break your opponent's force into chunks and deal with them as such. Archery, Sentinel Song, mobility, etc. are all part of this. Two of my typical opponents refer to my army as Trixie Elves.
Even before his change Thranduil's special rule made him a great leader. The ability to reduce the counter charge once per game could, when used right, help turn a tide. Now he's even more effective. Natures Wrath is a great complimenting spell for Wood Elves and even having multiple sources for casting it cheaply is great.
Heroic Combat is an action you should be doing whenever possible. If you can nail a fight with 2-3 additional warriors plus your Hero and then jump them to other Fights you can cause a lot of damage.
Throwing Daggers are something I used to use several of, being carried by Elf Blade warriors usually, but with the -1 rule I may not so much. Before though (or if you're not using the -1 move rule) they had about as much chance of wounding the model you were charging as you would in combat anyway (you hit at least 50% of the time and had the same Strength as your WE). They usually paid for themselves. With a hit on only a 4+ on the move now I don't know how good they'll be.
Finally, Elf Blades are often needed to crack tough enemy armor. Have a few scattered into your force.