They don't necessarily have to be long legs; in fact 10-15 nm will do fine.
Try plotting a round robin to a bunch of local airfields, especially the grass strips.
Of course it's much easier higher up
You do have to get used to looking at the map and finding the corresponding feature on the ground.
Cross-country glider flights are excellent training as you are usually zigzagging from one source of lift to where you hope to find more lift while progressing to the next turnpoint and eventually (if the lift holds) getting back home. The map comes out when there's airspace boundaries nearby or grass strips to find.
In the Southern Ontario farmland I fly over, towns are usually the wooded spots
