You can view a list of all Volume Snapshots for your account by navigating to Images, selecting Snapshots from the secondary navigation menu, and then selecting Volumes under the Snapshots section.
From there, select any Volume Snapshot, click the More menu, and select Create Volume to create a new Volume. You will then be presented with a window with options for creating a new Volume from the Snapshot, as shown in the image below.
From there, choose a Volume size, or enter a custom Volume size. The Volume size chosen must be equal to or greater than the size of the original Volume used to create the Snapshot. Next, select a Droplet to attach the Volume to (which must be in a region which supports Block Storage), enter a name for the Volume, and click on Create Volume to create a new Volume from the Snapshot.