The subject of illegitimacy often comes up. If you have Scottish ancestors and one of them was illegitimate, a useful source of information is the local kirk-session records. Unfortunately they are not as easily accessible as the old parish records (OPRs) which you can check on the Scotlandspeople website. I'm lucky in that I was living and working in Edinburgh when I started doing my family-tree research in the early 1980s and I could take odd days and half-days off my annual holiday entitlement to go to Register House - for B,M and D records, censuses and OPRs - and to the Scottish Record Office (now the National Archives of Scotland) next-door for kirk-session and other records.
In the Church of Scotland, which most Scots belonged to, the parish minister and the elders of the kirk comprised the kirk-session, which met weekly to distribute the poor's money, chastise fornicators, etc. A pregnant unmarried woman would be cross-examined about the father of her child, and a record kept of the proceedings.
For example, on checking the death-certificate of my great-great-grandfather Robert Stephenson in Melrose in 1863, I found that he was illegitimate, and his reputed father was one Hugh Stephenson, "teacher". I proceeded to waste about a year looking off and on at trade directories and other Borders records, looking for details of parish schoolmasters, until I had the brainwave of looking at the Melrose kirk-session records. There, I found that my 3 x great-granny Alison Moffat was summoned three times to appear before the session, and finally threatened with punishment for her "contumacy" if she continued to absent herself, so she finally and grudgingly turned up at the next meeting of the session and admitted that the father of her child was Hugh Stephenson, farmer in the parish of Gifford, East Lothian. That gave me a whole new area of research. I discovered that the Stephensons were a prominent Northumbrian farming dynasty who had taken tenancies of farms all over the Lothians and Borders, and John Prebble, in his book "The Highland Clearances", gives them "credit" for introducing into Scotland the new improved breed of Cheviot sheep that would eventually lead to the depopulation of Highland glens.
All down to checking the kirk-session records as a supplement to the OPR.
Harry