Step 1: The UP!
Step 2: First failures
Here are some mistares you might have done.
Step 3: Problem 1 : Nozzle too high
Step 4: Problem 2 : Surface not hot enough
Step 5: Problem 3 : The surface
PC Board : It will make your table higher (witch makes it easier to adjust the nozzle) and conduct the heat. I had problems with this one since I couldn't fix it perfectly to the table and it ended up curving because of the heat.
Green sticky paint : This substance actually comes with the printer. You have to apply a tin layer of this paint on the table and let it dry before to start printing. I found this method very ennoying because you'll have to repaint the surface often and it takes hours to dry. It also leaves a green mark on the part.
The MAGIC SUPER AWESOME blue painter tape : This one works perfectly. It might cost more than the two other solutions, but you can't miss with this one. You'll have to replace the tape once in a while, but it's worth it.
A new trick given to me by Lamedust is Kapton tape!
A little bit difficult to find but heat resistant and gives a shiny face.