1. How can I search for this on my own? I've tried expedia.com, but when you select 1 or 2 stopovers, it assumes that both directions of your journey are either 1 or 2 stopovers.
2. Also, is this truly cheaper than direct flights in both directions?
3. Are there any better alternatives to this plan? Does One-way versus return airfare tickets imply that it's more expensive to buy 1 single-way for the outbound, then 1 single-way with a stopover for the inbound?
To 1:) This is actually quite simple. For example, the search engine Kayak.com offers this: click on "Multi-city" and just add all the parts of your journey. Only list cities in which you want to leave the airport - there may still be layovers on the individual parts of the journey.
Note that this will find airfares that are for return flights (with stop-overs allowed) whenever there exist some for the journey.
Contrary to the post by @fkraiem, my experience is that most airlines websites do not allow to book such trips (so you will have to use one of the agencies listed by kayak or your favorite walk-in agency), or book them in very bad booking classes (so they cost a lot more).
A possible way to do 1 is to first use search engines to find out which airlines offer both flights with and without stopovers, and then book directly from the airline's website. Usually, you are able to select both legs separately among all their offered flights.
