Homebrew PCBs

I've made several PCBs with TT and must say that the last ones are 
getting really good.  The most important tips I've been following are 
this:

DO's
  1.- clean the copper well before transfering, I use thin metal wool.
  
  2.- try to use a SMALL Iron, like one used for neckties or for 
travelling, since it'll be easier to handle and will have a less 
bended heat-surface due to temperature.

  3.- Put the paper on the PCB and put the iron over it a few seconds 
to get a good working temperature

  4.- Use the iron's EDGE (NOT it's surface) to iron the whole thing, 
from time to time use the whole iron's surface to heat the PCB a bit 
and continue to use the edge, this warrants that every part of the 
drawing you are trying to transfer gets a correct amount of pressure, 
and the correct amount of heat.

  5.- Either put the PCB in water for some minutes and delicately get 
the paper out with your fingers or a toothbrush OR instead of using 
water pour some eatable oil over the paper, spread it well, wait some 
time for the paper to be really wet and try to rip the paper in one 
piece... I prefer the water-method

DONT's

  1.- DON'T just put the iron on top of the paper and leave it there 
thinking it's a matter of time for the transfer to be completed, in 
fact a few seconds will be enough if you have the right temperature 
and pressure and you will avoid overheating and possibly damagind the 
PCB.

  2.- DON'T use the whole surface of the iron to make the transfer, 
because since it is HOT it is also deformed and hence not completely 
straight.  This is the cause that makes you get some parts of the 
drawing transfered and some not, because some parts just don't get 
pressure! REMEMBER: use the EDGES to iron the drawing!!!!

  3.- DON'T scorch the paper, it has nothing to do with getting the 
transfer well, it only gets it all dirty!

  4.- DON'T overheat the PCB, since it will damage the bond between 
the copper surface and the PCB sustrate, there's NO NEED to put the 
iron several minutes over the PCB and get it cooked!!. Transfer 
doesn't work that way!!!

  5.- When ironing with the iron edges DON'T press it to much, since 
excesive pressure will spread the toner making difuse lines, just 
make 3 or four conscious passes pressing normally and you'll get the 
whole design transfered.

The best I've gotten so far using this tips is 10 mils lines and a 
good component density. Hope it is helpful!