I posted some of this in another thread but thought it useful to post it elsewhere.
One really neat trick I did was to print out the PCB layout slightly larger than 1:1 but 1:1 is also OK.
I then laid down all the components onto this and taped it to the desk so as I could not nudge it and mix up the components.
Then I started to paste the PCB and after this was done, I simply picked up the parts from the paper copy and laid them onto the board.
After this it went into the oven and hey presto, a professional looking PCB.
Regards
Dave...
