Step 1. Draw your shape. In this case a circle. I've made it a red line so it's easier to see. Make sure: a) The circle is "Made Whole",
b) There is no fill (Shift+Ctrl+F).
Step 2. Turn your chosen object (the circle) into a path. Do this by: 1. Click on the path tool, 2. Select the object, 3. Click on the "Convert the selected object to path" button.
Step 3. Put your text on this new object-shaped path. Write your text, or import it, or whatever. Once you have the text you want, select it, and then by holding down the Shift button, also select the path (our red circle).
This is where Inkscape stops being logical. In my last tutorial, I said that when I put text on a line, I had to use the "Generate from path" function. But this time, only "Text to path" seems to work. (Go figure...)
Step 4. Fiddle. My experiments suggest that the text won't always be in a complete circle. This can be corrected by shrinking in one direction...
...and then in another.
(There are also a couple of other ways of doing this, but I'll let you work them out for yourself by experimenting - which, though frustrating, is how you discover tricks...)
Step 5. Get rid of the red circle. Shift+Ctrl+F brings up the dialogue that allows you to choose "No stroke".
More fiddling allows you to change the perspective, create ovals, put on top of circles/spheres/other shapes, enlarge, etc.