This point is more or less an extension of the point above. If you want to avoid sounding awkward and long-winded, you need to know what you're going to say — every good sales voicemail is conducted with confidence and definitive intention. The key to delivering on both is having well-prepared, personalized voicemail messaging at your disposal.
If you’re contacting the same people with marketing voicemails and emails, you shouldn’t repeat information verbatim. By mixing up your approach, you make it more likely to get a response to at least one method. Also, your voicemails should be more personalized than your emails. For example, you could send an email to a contact – and 500 others – asking for feedback about a specific product they recently bought.

Conducting extra research on your prospects before you call them is always a good idea. This script from Mike Brooks is a great example of how you can use this additional information in your sales voicemails.
Try to avoid casual salutations like, “Hi” or “Hey” if this is your first time calling someone. Your introduction should be one or two sentences tops. From there you can move on to the body.