There are a vast range of different ways to organise this, limited only by the ingenuity of the operations department, with a cost-vs-revenue mindset applied to it. Some of the more noteworthy ones include :
A Netherlands carrier (maybe Martinair) some years had a range of low frequency/weekly operations from Amsterdam to various Caribbean islands. It would have been inconvenient to have crews stop for a week, and the inter-island schedules were not favourable, so they actually purchased a turboprop, I think it was a Bandeirante or Brasilia, and used it to move crews around. Of course, it was not just flight deck, but whole widebody cabin crews as well that they were taking.
Actually diverting scheduled flights to position crews or engineers. An example came to light in a press report when a BMI flight from East Midlands to Malaga was diverted to stop at Jersey to deliver an engineer and parts/tools to another BMI AOG aircraft there.
Chartering light aircraft has had a chequered background, there was a bad accident at Glasgow about 10 years ago to a Cessna 404 carrying a full 757 crew, which really put the kibosh on such arrangements afterwards.
My local taxi company here in London has a contract with companies at the airport and the drivers tell me that they sometimes get "brilliant" journeys moving crew - North of England being about the limit of their range. More than once they have apparently managed to combine the trip with repatriating some mishandled pax luggage upcountry as well !