Occupations: particularly if there was an occupation that got passed down through the family a lot. Seamen (merchant or navy) can be further researched; some occupations are strongly linked to a certain location, like my Furse family who were fishermen in Mevagissy for many generations (aka 'Fishygissy'!) For miners, you might want to check out which were the local mines, if there were any major accidents while your family were working in the area, etc. For farmers you might be able to find where the land that they farmed was.
Places: Find out about the places they lived; addresses, houses, reputation of the area, events. There was a Cholera epidemic in 1849 in Mevagissey; I can link this to a death of one of my relatives at the time. The area was evacuated and many people had to live in temporary dwellings until the epidemic passed - tents at Portmellon! In another case, while scrolling through burials at Truro, I found a smallpox epidemic in the mid 1700s - many deaths were marked to show which ones were from smallpox. Two adults noted as being from outside the area probably brought the disease to the town, but the vast majority of those who died were children - although none of mine were among the dead, you can imagine how frightening such an epidemic could be for the local people.
Also try
http://www.a2a.org.uk/ for other 'interesting' tidbits. One of my Furses was paid money for 'presenting and convicting' one Humphrey Smith of felony (he'd stolen goods from Peter Furse). Another ancestor, on a different line, was whipped in Truro for an unspecified offense (probably theft). One of the best ways to search, I've found is to use the format:
Surname NEAR10 Placename, so Blewett NEAR10 Truro should bring up all the Blewetts with some connection to Truro, for example.
