This post includes a step by step guide to manually clone a Database using Rman.
In some cases it may be useful to have the flexibility to configure and implement cloning manually or setup automatic or semiautomatics scripts to do this on demand.
Today this can be also easily done through Grid or Database Control clone capabilities.
To use cloning through Grid or Database Control you must configure SSH for user equivalence on both nodes , on the link look for: 'Configure SSH for User Equivalence'.
Once this is configured clone will proceed smoothly.