The easiest way is to use an agent to help you with your exact needs.

To do it in a ‘self service’ method you can do a multi-city search booking via an OTA that allows you to set your stop over times. Here is an example of a search with a 2 day stop in London before flying onto another destination:

You may find that the cost of doing this type of ticketing is cheaper than buying separate tickets for all the various legs…

You can also use it with open sections in the travel itinerary… and for one way trips…
Here is an example where you stop for two days in London, perhaps drive to Zurich rather than flying (the Prague to Zurich section is ‘missing’ for a flight) and your final destination is Sydney, Australia rather than returning to New York City. In this case it is a rather long one way trip, with a few stops along the way.

Change the class of ticket by sector, choose the airline to fly with, select the times to match your schedule. Today a good OTA can match the inventory selections of a live agent and even provide a better solution in many cases. Always good to have a human back-up if you need help in booking. That is why human online travel agents exist… we support your travel shopping by being just a chat click away.