GumbyGold: Thanks! I make them by steaming (or at least soaking in water) and bending thin strips of wood. Actually no power equipment is required using this technique.
I tend to use lighter woods like Maple, Birch, and Sycamore for linings. Mainly due to personal preference of having a darker wood on the outside - and having contrast - but also because I get requests for inscriptions (wedding dates, etc.) and those woods show the inscriptions better.
So far I can't say there are any specific combinations I shy away from.
I've done others with darker woods on the inside. Recently did a pair of Walnut rings lined with Koa that turned out better than I had anticipated.
Lately I've been working on a "Ring Customizer" for my website - for my customers, AND for myself - LOL! There are so many possible combinations, it helps to get a visual idea ahead of time on how the wood colors play together.
Thank you, Scrappy! Yeah - she really likes the ring! She actually got the idea for it using the beta/test version of the "Ring Customizer" I mentioned above. (http://www.stoutwoodworks.com/ringbuilder.php)
I've got lots to do on it still (and am considering taking some of the woods off - or at least having it flag certain wood combinations that aren't the best, structure-wise) ...but as-is it gives me some good ideas. ((Works in Firefox, Opera, Chrome, and latest IE…)