Homebrew PCBs

I read on the internet about using label paper without the labels to 
transfer the circuits. Pull the labels off, then run thru a laser 
printer. I have small circuits and can fit several on
a 4X6 pcb board.  The first time I tried it, I used Avery 3 across 
labels and out of 12 circuits on the board, 6 were useable and the 
lines were pretty sharp. The circuits on the outer edge didn't seem to 
transfer very well and were missing traces.  Then I tried the Avery 2 
across label and when I did the transfer the circuits seemed more 
fuzzy. This time, I ironed the copper board hot, then put the paper on 
it and ironed for another 3 or 4 minutes. On a 4 circuit sheet, I only 
had a couple that seemed to be ok to use. There seems to be some pads 
that are touching under a transister that I can correct. Has anyone 
else used the label paper. Are there some tips that anyone can give to 
make this more of a science than an art?

Thanks