**House Rule: Ask your DM for more skill points.**

Ask your DM if increasing [Intelligence][1] will grant retroactive skill points (the way that [Constitution][2] grants retroactive hit points.) If he allows that, then that would give you a lot more skill points to put into [Use Magic Device][3].
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**[Shapechange][4] into a creature that has the spell you want to cast.**

If you want to cast X, then shape-changing into a creature that _can_ cast X would be a worry free option. Many outsiders, for example, have plenty of divine spells at their disposal. Just flip through the pages of various books and keep a list of what monsters can cast what.

Best example is:

  1. [Solars][5] cast spells as 20<sup>th</sup> level clerics - which
    includes [Miracle][6]. And like Wish, Miracle can duplicate spells. A Solar's spellcasting is a natural ability - there is no reason you wouldn't get it with Shapechange.

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**Have a familiar that can cast for you.**

I am assuming any wizard can trust its familiar. Ravens, for example, being able to speak a language can activate the spell trigger on items. Put some of its cross class skills into Use Magic Device and start handing it scrolls. You can use items to pump your familiars skill check up significantly prior to making the rolls to help out with its lack of skill ranks.

  [1]: http://www.d20srd.org/srd/theBasics.htm#intelligenceInt
  [2]: http://www.d20srd.org/srd/theBasics.htm#constitutionCon
  [3]: http://www.d20srd.org/srd/skills/useMagicDevice.htm
  [4]: http://www.d20srd.org/srd/spells/shapechange.htm
  [5]: http://www.d20srd.org/srd/monsters/angel.htm#angelsolar
  [6]: http://www.d20srd.org/srd/spells/miracle.htm