When planning a new journey I like to collect interesting sights in the countries I’m intended to visit. Articles in magazines, news items, documentaries, other travelogues and other sources of interest I put together in a Google My Maps map. Then when the time of departure is in sight I connect the points of interest together and create a route. Of course this route is often deviated from.
For each point of interest I describe what is to be seen there. Also places to spend the night are added when I hear of good ones, iOverlander also is a good source for this. Other good sources for points of interest are the UNESCO World Heritage list and the World Database on Protected Areas.
The Google My Maps data can be exported into KML/KMZ and in that way imported in other mapping tools and apps.
On the road I like to use Maps.me for navigation, which is available for Android and iOS. It provides offline maps and routing of all the countries on the world. The mapping data Maps.me uses originates from Open Street Maps, a community driven mapping source. In general these maps are very sufficient.
As a backup on the road I use a Garmin GPSmap 60CSx, which also supports the maps from Open Street Maps and routing, however the interface is much more cumbersome than your average smartphone or tablet.