One item from 5th edition that did not make the transition to 7th is the "makeshift staff". This handy little item allowed a Wizard to enchant any old piece of wood into a temporary magic staff.
Earthsea fans will doubtless remember the scene where Sparrowhawk grows a new staff from a blade of grass. I am not sure that the original intent was to allow quite this dramatic an effect, but I see no reason why it should not.
Not seeing any reason why 7th edition Wizards should miss out on the fun I have decided to write up a "Makeshift Staff" spell.
Makeshift Staff [Cosmic]
Level:1 WIZ Cost:1 Range:Touch
Duration:Permanent (but see below)
Description: Enchants any appropriate common object to serve as a temporary magic staff. For the duration of the spell the makeshift staff functions as a Staff Ordinaire.
The first time the obect is used to cast a spell the Wizard needs to make a Level 1 SR on WIZ to see if the object is able to withstand the flow of magic. If the SR fails, the object explodes. If the makeshift staff does not explode, the Wizard can cast spells with a total WIZ cost of up to twice the mage's INT. The final WIZ cost paid by the mage to cast the spell is what is counted, not the base cost of the spells. When the total number of WIZ points has been cast through it the makeshift staff burns out and may no longer be used as a casting focus.
In looking over the 7e magic rules I also becamemore aware of the subtle differences between a "Staff" and a "Wand". A staff provides a reduction in spell cost equal to the Wizard's level. A wand provides a reduction of 1 point as well as doubling the cost reduction for casting spells at lower level.
It is not specifically stated in the rules but I assume that either enchantment could be placed on an alternative focus object. Thus an enchanted brooch might be found that functioned as a Staff Ordinaire, or a rune inscribed ring might function as a Magic Wand.
T&T is your game now, fell free to adjust the "special effects" to suit your own taste.