Here are a couple of nice rook endings from Most Instructive Endgames of 2012-2015(Naiditsch and Balogh,Cs 2016)

The authors present 80 nice endgames.

Possibly you fought hard and won a P. But how to convert in a rook(or double rook) ending.

Endgame 35

Aronian Karjakin, Tata Steel 2014

After 46,,Kf6(Diagram)

White is up a clear P. How to best convert?

After 46..Kf6

After 42.Kg2

Endgame 41

Wojtaszek-Eljanov

Gashimov Memorial 2014

After 42.Kg2(Diagram)

Black has a clear P+ in a complicated looking RR-RR ending. Again, how should Black convert?

After 42.Kg2