Hello Marco and welcome to PSG.
I would use the Pen Tool.
There are two options. The 'Stroke Path' option and the 'shape' option.
I would do this on a separate layers and in sections.
For the
Stroke Path option.
Set up your Brush Tool to the size and color you desire for the stroke.
Use the Pen Tool to create a path.
When you have the path completed, right click on the path and select 'stroke path' from the menu, don't select 'simulate pressure'.
Repeat until done.
Or you can use the Pen Tool set to shape.
Set up your options by turning off the fill and setting the stroke color and size.
Set the
Shape stroke type to line, the align option to center, and the corners to sharp.
Again I would use separate layers for the different section of the subject.
Use the Pen Tool to create a stroked path around the subject.
This option gives you the ability to edit/alter the paths to make small corrections if needed than the first option.
