My favorite mid-levels trick for wands. It is campaign specific though, since Action Points are only used in Eberron (unless we talk about the ones in Unearthed Arcana which are even better).
What you need:
Extend Spell (PHB)
Persistent Spell (Complete Arcana)
Wand Surge (Magic of Eberron).
Unfettered Heroism (Races of Eberron).
The ones that can pull it of:
Wizard/Sorcerer or Bard into Incantatrix or
Artificer with Etch Minor Schema.
You apply Persistent Spell to Unfettered Heroism either through the Incantatrix class feature or the Artificer infusion to add a metamagic feat to an item. In the latter case, you need to craft a Schema of Unfettered Heroism. Schemas are found in Magic of Eberron and works like a permanent scroll that you can use one per day.
Now you gain 1 action point per round, but it'll disappear at the end of the round if you don't use it.
This will go on for 24 hours.
Through Wand Surge, you can burn an action point instead of a charge to activate a wand or a staff.
You can now activate your wand for free.
Or your custom built Staff of Avasculate for that matter...