Demonology Warlock uses his summons pets to support its damage, has one of the best raid buffs in-game with [Demonic Pact] increasing spell power based on the amount of spirit. Recent calculations have put the importance of [Demonic Pact] on the same level of Bloodlust has the buff is constant.

Gems and Enchants for Demonology Warlock Wotlk

Demonology Warlock Enchants

Head

[Arcanum of Burning Mysteries] – Kirin Tor

Shoulders

[Greater Inscription of the Storm] – The Sons of Hodir

Cloak

[Enchant Cloak – Greater Speed] – Enchanting

Chest

[Enchant Chest – Powerful Stats] – Enchanting

Wrists

[Enchant Bracers – Superior Spellpower] – Enchanting

One Hand Weapon

[Enchant Weapon – Mighty Spellpower] – Enchanting

Two-Hand Weapon

[Enchant Staff – Greater Spellpower] – Enchanting

Hands

[Enchant Gloves – Exceptional Spellpower] – Enchanting

Waist

[Eternal Belt Buckle] – Blacksmithing

Legs

[Brilliant Spellthread] – Tailoring

Feet

[Enchant Boots – Tuskarr’s Vitality] – Enchanting

Demonology Warlock Gems

Meta Gem

[Chaotic Skyflare Diamond] +21 Critical Strike Rating and 3% Increased Critical Damage

Requires 2 blue gems

Red

[Runed Cardinal Ruby] +23 Spell Power

Stats/Blue

[Nightmare tear] +10 All Stats

[Purified Dreadstone] +12 Spell Power and +10 spirit

Orange

[Potent Ametrine] +12 Spell Power and +10 Critical Strike Rating

[Reckless Ametrine] +12 Spell Power and +10 Haste Rating

Notes

Gems and enchants should be picked depending on the stats needed. Example: If under hit cap gem and enchant until hit cap, following the stat priority. Orange is a good choice if the bonus is + Spell Power and relevant. Professions bonus are always better than the listed enchants and gems.