Its a shame that warlocks that take a prestige class will likely never see the opportunity to get the Imbue Item ability (12th level of warlock). Here is Imbue Item as a feat for warlocks that took a different direction in their warlock career.

Imbue Item [General]
You have taken an unorthodox route to increasing your power as a warlock. As such, you did not gain imbue item by virtue of leveling up in the warlock class. Instead, you take imbue item as a feat to gain this ability.
Prerequisites: Deceive Item (Ex) class feature. Use Magic Device 14 ranks. Warlock caster level 11.
Benefit: A warlock with this feat can use his supernatural power to create magic items, even if he does not know the spells required to make an item (although he must know the appropriate item creation feat). He can substitute a Use Magic Device check (DC 15 + spell level for arcane spells or 25 + spell level for divine spells) in place of a required spell he doesn't know or can't cast. Imbue Item is a supernatural (Su) ability.