Have become recently obsessed with touring (I go through these phases). To that end I have been looking on Craigslist for a touring bike and was wondering what are some obvious things I should look for? I do some basic maintenance items on my bikes (flats, clean/lube chain, re-cable/adjust brake/derailleurs,…) but I am not a bike mechanic so some of the subtle items may get by me. Specifically the frame, what would be considered a show stopper?

Any info would be appreciated.

Thanks.