How to reset a vulnerable Windows XP VM for learning Metasploit?

I am attacking a vulnerable Windows XP as VMWare VM using Metasploit. (learning Metasploit)
How can I reset the machine to a state before attack?
Is a snapshot sufficient or should I clone the machine?

I'd recommend making a snapshot of the 'target' computer before attempting any exploit.
Prior to taking that snapshot, ensure the target VM is patched (or not) to the extent you like/prefer, as well as configuration settings/parameters. Then yes, take a snapshot. Name and date it something meaningful and significant.

You could do a clone, but that is time and space consuming.

Once you've exploited the target you can endlessly 'revert' it to its pre-attack stage, by restoring back to the snapshot you took.

If you want a good exploit on XP turn firewall off.
What I do is make a copy of the vm zip it and save it some ware safe.
When you then start the VM take a snap shot Call this one do not toutch. Make one more and start playing around. When you mess it up revert back to the one before the do not toutch version.
Works like a charm.