(Just found this forum, and am looking forward to learning form others and passing on things I know, so here goes...!)
I haven't tried using Elder due to the old superstitions about elderwood and fires, (although fallen elder would probably be ok
), but what I have used is Hazel for the spindle, and pine for the hearth, both to great effect. This is particularly useful as hearths can often be a pain to make, especially if you're dealing with old scraps, and pine is readily available (if not traditional) in DIY stores, old palettes etc.
The only woods I would recommend against are oak (very hard, and takes ages to get enough dust) and anything very resinous (pitch pine, cedars, firs, balsams etc) where the resins tend to glue the dust together stopping them heatig up properly.