I am in agreement with Paul most mahogany can be bland to get some ideas take a look at Jims pens with segments in them the same can be done with any wood mix and match some of our own home grown woods are very plain bland Sycamore, chestnut, Box, Ivy to mention a few but pens get made with all of them in my opinion any wood is worth a go just that some benefit from being dressed up there are no limits to what you as a turner can create the only limits are your own imagination explore, experiment and enjoy.
Personally I don't like turning mahogany nor Oak but that don't mean I wont ever turn it and that you should never turn it if you fancy giving it a go then go for it its your hobby no one else's