There seem to be a lot of new necron players out there who are looking for comments on army lists or tactics - but many are making the same bloopers when it comes to setting up their armies. I'm one of them!!
So, I thought it would be helpful to list some of the really good units/combos and the combos that generally don't work together (or at all!). You don't have to give away your secret tactics (although you can

) but lets just highlight things that do/don't work.
I'll add things to the categories as they come up - dissent over categories will be resolved by

. To help us newbies, a quick comment as to why useful/not useful would be appreciated.
Have I got it wrong? Happy to fix it.
The categories are:
Awesome
Overlord on Command Barge : Must have warscythe and
MSS, preferably with
SW and/or
PS.
Wraiths : In groups of 5 or more, with 3 whipcoils and 1 particle caster for wound allocation.
LanceTeks (Harbringer of Destruction with Lance)
Solar Pulse
Army lists with a clear focus
Mindshackle scarabs and warscythes. No, these aren't optional
Spyders and Scarabs - Who cares that you cannot conga line them? What are solar pulses for? Send three squads of ten at your opponent turn two/three ...[felixcat]
ResOrbs [felixcat]
Annihilation Barges : Cheap and effective.
Good
Death & Despair combo (D&D) : 5 Deathmarks and a VeilTek - good suicide unit for putting hurt on well, anything. You will probably only get one turn of shooting so make it count.
Anrakyr upgrading Immortals to Eternals, preferably a group of 10 with a StormTek (and a lord with orb if you have points)
5 Sword and Board lychguard with VeilTek and Lord with Orb (or
HQ unit) : Takes a lot of fire to kill these, good in
CC (but wraiths are better). Lychguard are an alternative if your
FA slots are full (of scarabs for example) or you want a body guard for the
HQ unit. For max fun, drop at the same time you drop a D&D unit.
Stalkers (2 of) with a shooty army (No, annihilation barges don't count).
5 warriors and a Lancetek (or 2) : Good anti tank squad, dies quickly in
CC.
Lance courts in ghost arks - this is our strongest
AT unit in the codex [felixcat]
Writhing Woldscape and tremorstaves - this just debilitates mech armies. [felixcat]
Warrior blobs - ten warriors with a ghost ark nearby - try and kill them. [felixcat]
Praetorians - Maybe they are an unusual choice for many. Stick a
DLord kitted out with them and use them as support and they perform very well with void blades.[felixcat]
Meh
Monoliths (I haven't played these, is this fair?)
Destroyers. They are too pricey and too fragile.[Puscifer]
Fail
Flayed ones without Imotekh
Doomsday Arks without stalkers - some say doomsday arks at all!
Stalkers in a mostly
CC army : there is no benefit from twin linking.
1 of anything : you know the phrase, never take 1 when 2 will do. Now here we need to be a bit careful because in some circumstances adding 1 will complement a list (eg 1 anni barge with 2 command barges) but in most cases, its just a target.
3xWraiths (true?)
EPIC FAIL
Walking Lychguard : Use wraiths instead
Imotekh in a shooty army
Blobs of warriors with no phaeron (you can't stand still forever).
One of every unit. Just...no.
Any list with no crypteks or lords. Cheap force multipliers and you didn't bring any???
Also check out
http://www.reddit.com/r/warhammerFAQ/comments/srb2e/necrons_w40k/
for more advice and analysis of units! [Thanks Skoffs for the link]
Building a Necron List:
As with any army list, you need to consider how units are going to work together. Also, sticking wraiths, anni barges and
CCBs into a list with a couple of troops isn't going to necessarily win you games. There are so many different combinations and synergies, you need to put thought into how you are going to play each unit. Also, if you find a unit that is going to do what you want, go ahead and try it even if inter web says it won't work. It might work for your play style and in your list.
However, see below for some common things that tend to happen in newbie lists:
Effective:
a) 5 barges : With 2
CCB and 3 Anni Barges as a base, it is difficult to create a list that will totally suck. Reduce prorate for smaller point lists.
b) A wraith unit (5x, 3x whip coils with 1 Particle Caster). Having a wraith unit helps a lot with close combat protection - can be used aggressively or defensively. Multiply X 3 for wraith wing, but you need to support the wraiths cos they can't win the game by themselves (almost, but not quite.

)
c) Zahndrek and Obyron together. Great synergy.
d) Scarab units (5 bases minimum, but I prefer 6). These are great tarpit and
AT units, with a good threat range. Combine with Zahndrek furious charge and you can make a mess of T4 units.
Not Effective:
a) Shooty List with Imotekh. Generally, there isn't a lot of synergy about using Imotekh to make it night fight, then cramming your list with stuff that needs to see to shoot. So, stalkers, lots of lanceteks etc - maybe you want to rethink Imotekh
b) Obyron by himself. Can't take a court and he can't take a barge. Unless you really need another vod, avoid this.
c) Foot lists i.e. Big blocks of warriors without phaeron. Also, without a ghost ark to replenish.
What do you think? What is your pet hate in Necron army lists, or the thing you most like to see?