Sougujutsu, the art of tool use, is a fairly underused section of ninja skills. Often people just combine this category with Ninjutsu, saying that ninja techniques is the general category and Genjutsu and Taijutsu are specialties that should be separate. Most successful ninja have a good foundation with this category, as it teaches stealth, camouflage, traps, tag use, and intelligent tool use.
Defining Sougujutsu
Sougujutsu revolves around the use of tools with chakra as a secondary part of the technique. A major section of Sougujutsu is the art of Puppetry, which requires the use of a puppet to perform any jutsu of that category. Some ninjutsu includes use of tools in the jutsu, but the tool is not the primary part of the jutsu and thus does not qualify the technique for this category.
Types of Sougujutsu
Tool Techniques
This category of Sougujutsu makes use of the large number of tools a ninja has at their disposal. Wire work is part of this category. Items involved in techniques from this category include kunai, senbon, shuriken, wire, scrolls, combat tags, makibishi, and umbrellas. This category typically holds trap techniques, demolition techniques, and many effective combat uses of tools.
Puppet Techniques
As the name suggests, this category handles all aspects of puppetry. Puppets require great skill and chakra control to use. Given the number of traps, launching mechanisms, and other items littered within a puppet that require activation for use, those that can use multiple puppets in battle are quite dangerous.
A part of this category is Kugutsu no Jutsu. This is the specific term for how puppet users control their puppets, but most people refer to the technique as Chakra Strings. Some people have learned how to make and manipulate chakra strings for use in areas other than puppet use, such as holding and throwing large numbers of kunai simultaneously.
Non-combat Techniques
This category mainly consists of skills that can require little to no chakra and involve basic skills a ninja should have. This category includes general stealth training, cheating skills, and escape training. Some of the skills used in those categories are actually ninjutsu, genjutsu, or taijutsu, but the basics those skills are applied along side come from here.