Start Skype and choose Tools→Options→Calls→Voicemail from the main menu.Put a checkmark in front of Send unanswered calls to voicemail.Just click the Record button (the green button with the triangle) and speak the Voicemail greeting you want callers to hear.Click the Stop button (the red button with the dot) when you're finished recording.Click the Replay button (the red button with the backward arrow) to listen to the message you just recorded.When you're satisfied that you recorded the perfect message, click Save.See More....
If you persistently can’t save your greeting, you may need to reset your phone’s network settings. The iPhone needs to access your network’s data connection to save changes to your voice mail configuration, and if it can’t connect to 3G or 4G, it won’t save the changes.

Have a positive attitude while recording your voicemail greeting — it will carry through in your voice. If you find it difficult to convey positivity over a phone system, try smiling while you’re recording. (We promise, you will hear a difference.)
The simple truth is that you need to be more aware of what you’re leaving for other people to hear. Sure, this doesn’t always register as a priority for users, but it’s never too late to reassess your greeting. a. Reading/Speaking in the Imperfect Tone: Tone is absolutely everything. Users don’t want to come off as being too nice, as it sounds insincere, or being too terse, as it can be interpreted as being rude. That being said, striking the right balance is absolutely essential. Your greeting exists as its own entity, and therefore, it should NOT rely on callers’ familiarity with you. Instead, it needs to appeal to the masses. As such, your inflection, i.e. the way you state your name and directions, needs to be both welcoming and firm. b. Injecting Humor & Insincerity: While humor/light heartedness can be welcoming, it can also convey a sense of informality, insincerity, and ultimately unprofessionalism. Why, because you’re not there to lend your humor or to contextualize. Instead, you’re assuming the caller has a working knowledge of your personality to ground the message. Though this might not sound like it’s all that terrible—it can be detrimental. As stated above, one should NEVER rely on a caller’s familiarity with you. Instead, aim to appeal to the masses. Humor is ultimately subjective, meaning not everyone has the same tastes; therefore, someone is bound to be turned off by a quirky or off-color remark. While implementing a light-hearted or even tongue and cheek tone can work, it’s just a really bad idea.