Tom - I have not used toner transfer.

I do know a guy who does use toner transfer, and this is some of his work:
http://we.easyelectronics.ru/uploads/images/00/22/11/2012/01/09/acc84...
http://we.easyelectronics.ru/uploads/images/00/22/11/2012/01/09/cf9d5...

It is a single sided PCB for an ARM (STM32F) processor, the pins on the
processor are on 0.5mm pitch.

He can get 0.15mm track and space (about 0.006 of an inch), and is working
on reaching 0.1mm (about 0.004 of an inch).

He sent a link to these examples of using toner transfer, which use a  
different technique.
http://we.easyelectronics.ru/uploads/images/00/22/11/2012/01/09/cf9d5...

The image is printed onto aluminium foil, and the foil is 'ironed on' to
the PCB, but not peeled off, it is etched off. It isn't necessarily more
reliable (he says less than 1/2 the images on the foil are usable), but the
fineness of line is outstanding.

There are 'commercial' 'press-and-peel' toner transfer systems, but the
ones I've seen are sufficiently expensive that I don't use them.

Everyone else I know (including me :-) uses photosensitive PCB's and laser
printed stencils. The results are pretty good.
I have the offer of the use a 'proper' etching tank, and UV exposure box.
The etching tank is noticeably better than traditional Ferric Chloride
trays (sharper edges, finer lines). So if folks wanted to convert a design
to a PCB, and could wait a few days, I could use that process for them.

The tricky parts are keeping everything very clean when exposing the board,
and getting a good UV exposure time.
I could UV-expose the board, and we do the etching at fizzPop by hand. The
chemicals should be properly disposed of, not just down a sink.

I've also done 'hand etching' with photosensitive PCB. My chum David had
his UV box calibrated, so it was very straightforward.

Folks can draw directly onto PCB material using an etch resist pen, e.g.:
http://www.rapidonline.com/Tools-Equipment/Etch-Resist-Pen-34-0300/?s...
I did that (a while ago) at school. Much cruder than laser printed
stencils, but very direct technology. Okay for transistor circuits, but
would need quite a lot of care for integrated circuits.

When I was a kid, we had sets of sticky-down outlines for ICs from
Letraset, but I haven't found those.

GB-)