Im playing a vampiric necro build with my dark elf, I specialize in:

Necromatic conjuration- conjuring skeletons and raising undead.

Blood magic (with help of mods)- branding one handed weapons with lifesteal, lifetap over time spells, health increase buff, health regen buff, blood bolt and aoe life tap. All spells utilize health instead of magicka.

Enchanting- taking souls for my own bidding, to add to my grim reaper esq playstyle.

One handed axe- im able to cast a spell on my axe that allows it to steal life, can be coupled with lifesteal enchantment. This was gonna be a trial and error thing but the added weapon fits perfectly into the playstyle.

Two handed axe- 2 handed axes are very grim reaper/executioner esq. With mods, I plan to craft endgame scythes that are goverened by the two handed weapon tree and plan to enchant them with soul binding.

Frost magic- necromancers/vampires love frost magic and this servers as my ranged offense. I also utilize frost runes and frost cloak.

Poison magic- with mods I can summon bug swams, spray locusts, surround myself in a poison aura and place poison and paralysis runes.

Dark robes (no alteration)

No sneaky sneaky stabby stabby, I'm a grim reaper/lich, you shall face and fear me.

Eventually id like to spec into fear from illusion and some restoration to increase my blood magic potency.

As I leveled since the beginning, I've chosen to boost only magicka and health, with more emphasis on health, coupled with blood magic I can be quite tanky.

Cool.

You will need high magicka for those Uber-level Necromancy spells. So don't neglect it too much.