Echoing spell+Extend Spell.

Basically with this one feat via Sacred Geomancy, you double the spell slots of any spell 3 levels under your highest. as a 7th level wizard if you roll well enough/can math good enough you get to cast each of your 1st level spell slots twice. And it only goes up from there, because who doesn't want 10-12 castings of their low-level utility spells at that level, especially if the second casting is at double duration (hooray extend! as the option to add SG to a spell is done upon casting the spell, not during your preperation).

Note you can also apply non SG-gained metamagic feats to SG'd spells, so your level 5/10/15/20 bonus metamagic can apply to these too.

And as a wizard, it's not hard to get a stupid high spellcraft, allowing you to easily cast most (if not all) your spells at an additional +1 caster level.