I'm not sure if I understand your question. But I'll try.
When you say "UI design", I think UI means User Interface. What kind of UI is it?
Like with so many different tasks, in Inkscape there are often more than one way to do it. And most of the time, it's a personal choice which way you do it.
If you hold Shift and Ctrl keys while you drag the Ellipse tool
it makes circles and draws from the center point. (Ctrl makes it a circle, and Shift makes it draw from the center.)
Using Snapping, you can be sure that the next circle you draw is concentric, because it will start from the center of the first circle.
http://tavmjong.free.fr/INKSCAPE/MANUAL/html/Snapping.htmlIf the circles need to be a specific size, you'll need to draw them first, and then make them the correct size. If you use Object menu > Transform > Scale, the circles will be scaled from the center. So that will allow you to keep the circles concentric. (If you use the Selection tool, and enter the dimensions in X and Y field, the circles will be scaled upwards and to the right, rather than from the center.)
Another way to do it, would be to draw all the circles first and make them the right sizes. Then you can use either Align and Distribute dialog
to align them, or you could use snapping. Although to snap circle centers, you have to give the circles a fill color (temporarily). I've always found that annoying, but that's how it works.
For A and D dialog, select 2 circles, and click "Align on vertical axis"
and then "Align on horizontal axis"
. For the next circle, be sure to set "Relative To:" dropdown menu to the proper option, depending on your selection order.
I don't know what kind of "minor details" you're planning to add. But I wanted to mention the option of locking the circles, so that they don't accidentally get dragged out of alignment. So you can either use Layers, and lock the appropriate layers, or using Object menu > Object Properties dialog, you can lock individual objects. Oh, and I think you can do that with the new Objects dialog, and perhaps easier than opening Object Properties. (Or also, hiding layers might be better than locking, depending on your needs or preference.)
I notice in your illustration, it looks like a polar grid behind one of those things. Extensions menu > Render > Grids gives you options for several different kinds of grids, inclusing polar. And did I see a new LPE for grids? Ahh no, it only makes rectangular grids.
If you need to make tick marks around the circles, like the hours or minutes on a clock, you can use Path Effects > Ruler. Or of course there are plenty of ways to use simple geometry to draw lines like rays coming out from the center of a circle.
That's about all I can think of, without more info from you. But just ask if you have more questions
Edit
Just thought of something else. With the Ellipse tool, you can also draw arcs and what I call wedges, although there's another word for it, that I can't remember. So you can use that feature to create rays at certain angles. Notice those tiny circle handles, after you finish drawing a circle or ellipse? You can drag those, and then you can see what they do. To set the angle, enter the numbers in the Start and End fields on the control bar.
