Preparations

Before starting to make a PCB, you should already have a layout. You can use any electronics program capable of designing PCBs. Most people in Germany use Eagle. for this. I prefer to use Ulticap/Ultiboard from Electronics Workbench. A few years ago you could buy this program as a Studio-version for private use. The only difference to the full version was the lack of gerber-drivers, which are needed for profesional PCB manufacturing. Since I make my own PCBs und use a normal laser printer for this, the Studio version is sufficient for me.

After making the layout, it is best to use a laser printer to print it on a sheet. Don't use regular overhead sheets for this, but rather sheets which are not so smooth. I usally buy those sheets in a copy shop (about €0.50 per sheet), but it is also possible to buy special sheets, like for example those from Conrad. I've tried these sheets, but couldn't find any difference compared to my normal sheets, even with quintuple price.

Two tips for the sheets:

1. The layout should be printed mirrored, so the printed side of the sheet will lay directly on the photoresist later on.
2. Because the sheet becomes pretty hot in the printer, they could deform a little when making double-sided designs. Therefore is is best to let the printer cool down a bit between printing two sheets. This should minimise the deformation of the sheets.