Begin by opening up a new document in Inkscape. Let's start by making the saucer that the coffee cup rests on. The saucer will be comprised of five different ellipses, so get ready to draw. Select the Circle/Ellipse tool (F5) from the Toolbox. Then draw an ellipse about the proportions of the one in the picture below.
Now we need to change the fill and stroke (outline) colors, so select your ellipse and open up the Fill and Stroke dialog window by going to Object > Fill and Stroke (Ctrl + Shift + F). On the Stroke paint tab click the "X" button to eliminate the outline on this shape.
Now we want to fill the ellipse with a radial gradient. We'll be doing quite a few radial and linear gradients in this tutorial, so pay close attention if you've never done this in Inkscape before. On the Fill tab (still in the Fill and Stroke window), click the Radial Gradient button. Inkscape automatically fills your shape with a gradient - normally fading to transparent by default.
We want a gradient with two shades of gray, so click the Edit button underneath the gradient. Now you can edit the gradient's Color Stops and their Transparency. Set the first Stop to a light shade of gray (ddddddff). Set the second Stop to a darker shade of gray (b2b2b2ff). Make sure the Transparency for both colors is set to Opaque (no transparency).