The tools I use in my trade are: my experience and education, computers, cell phones, a digital camera and the internet. The software I use for the computers are sometimes expensive and complicated, such as Revit and AutoCAD, and all the Adobe programs. There are also some free or student copies that can be had for learning, but registered software is essential to working with teams of other professionals when exchanging and combining files. So, I have a big investment in acquiring them and training to use them professionally.
The profession of technical illustrator, draftsperson, CAD technician and Lighting Designer requires this, but I am sure there are many businesses and working groups who do things differently. For me, not having any employees, not having much in the way of business overhead, and a degree of freedom is a primary requirement. So, I have software called Logmein that lets me connect with people on the internet, show them what is on my computer screens. I can do a show and tell as though we were together in a conference room. Distance is no problem, time is by appointment. There are no cameras involved, it is just a connection to my computer from another computer and my “guest” can use their keyboard and mouse if I am tutoring, and they want to practice a command. A lighting design client can use the mouse to point to an item in their project they want to discuss, change, review or move.