I'll try not to clutter this section with too much esoteric stuff, just things that have worked for me for the time being. I've started off with some thoughts on following up on Methodists in Ireland, followed up with quite a few suggestions for tracking down Monumental Inscriptions in some more obscure places. Finally, I've shared my favourite sources found so far for tracing medical men and clergy.
I hope these prove useful and feel free to nominate your favourite spicy sources too!