Hey, guys, looking for a little advice.

I don't have a terrifically large druchii force. I started with another any that doesn't seen to match my play style very well, so I'm looking to build my dark elves out a bit.

My initial purchase was an auction that landed me the following:
Malekith kit
20 darkshards
20 corsairs
1 supreme sorceress on foot
1 sorceress on foot
10 cold one knights
1 bolt thrower

So, I'm looking at adding slowly. I have the advatage of a group that really enjoys the End Times and Host of the Eternity King. Two friends are high and wood elf players so we can pitch in back and forth. But, I do need to get my own army up to scratch.

I had been considering getting started with a set of dark riders/warlocks, but hasn't decided where to go from there.

I'd appreciate your suggestions. Thanks in advance

By adding Dark Riders and Warlocks you actually have a decent starting army right there. You could add another bolt Thrower, because they are more fun in pairs (or threes).

Anything goes from that point forward. If you prefer more mobility, you could add another fast cavalry unit, some Shades or a character on a pegasus. A monster or two could also be thrown in.

One of the advantages of the End Times list is that we don't need a lot of other models if we have Malekith

Your existing choices are a good start.

And your idea of Dark Riders/Warlocks an ideal expansion. I'd go for 10 of each at least.

After that:
- three more bolt throwers
- 10 Waywatchers (or Shades)
- a Pegasus character


...and you should be on your way to a mobile, elite force

Disclaimer:
Daeron was posting while I was posting. +1 to his comments.
Playtest with proxies first to ensure you enjoy the playstyle and troop choices

You guys are quick! Thank you.

My initial force is Lizards, and I've discovered I'm much more inclined to soften the enemy from range and engage, which lizards aren't great at. Bolt throwers, crossbows and dark magic do a bit better than javelins and magic. For me, at least.

I've also been considering more infantry. I'm just unsure where to go there.

Are there any considerations I need to make if I start eyeing giant monsters? I've gotten the (possibly wrong) impression that druchii monsters are probably better left at home (minus Seraphon).