Building the base mesh using the Skin Modifier
So this is my first attempt for a base mesh. I wanted to try the Skin-Modifier-method myself in order to get a better feeling for this approach:
The other two methods I know of is to:
1) use a set of (different) mesh primitives for building a rough shape and merge them together with the Bool-Tool-Add-On (part of default Blender distribution but has to be activated in the preferences)
2) use one mesh primitive and bring it into shape with the sculpting brushes
PS: When uploading images, I always have to abort the first upload try because it doesn't finish. Only the second upload try is successfull.