Arthur C Clark once remarked that any sufficiently advanced technology is indistinguishable from magic.
Looking at this from the other end, what if magic is the technology of a fantasy world. If this is true, there are some interesting consiquences to the way magic works and how it is used.
Firstly magic is used to make life more comfortable (why muck around with messy fireplaces when, with a few simple enchantments, you can have central heating).
Secondly magic becomes more ceremonal in nature (you're not going to die in the next two seconds without a working central heating system and once it's in place it will be there for years so it doesn't really matter if it takes several hours, or even days, to set it up).
Of course there will still be the munchkin element who just want to lob fireballs around, but they will be few and far between (this is a lot harder to do - and a lot more dangerous).
Practical wizards in effect become craftsmen, producing a whole range of magical items and in-place enchanments and, like all craftsmen, they will produce items that have a ready market.
Now, the vast majority of ordinary peoeple are not really intersted in lobbing fireballs at dragons (that's the sort thing that only insanely suicidal adventures get involved with). Instead what most people want is creature comforts (central heating, freezers, televisions, etc), so this is what the wizards make.
Result: a magical toaster is common place, you can buy one in your local village shop, but a wand of fireballs is virtually impossible to find.
I don't know if this would work (I haven't actually tried it), but it's an interesting idea don't you think.