One of the best sales tactics I use is actually combining cold calling with cold emailing. I mixed the two up about 2 years ago and have found it to be a super powerful technique that is easy to do as you are sending pre-recorded messages and you have less chance to mess up as appose to a live cold call.
Below is a video showing this video as well as an easy to follow script I use. Try to keep the message around 30-40 seconds in length.
“Hello Jane,
I hope all is well.
I choose to send you a voice message rather than cold calling you.
The reason I am getting in touch is that I noticed you are recruiting for a [Vacancy Name] and wondered how this is going for you as I typically work with local companies as a talent partner for the tricky to fill positions such as [Vacancy Name].
I would be happy to open a dialogue with yourself at any point should you wish to discuss how we could be of service.
You can reach me on [Your Contact Number] or email me back.
Look forward to hearing from you.”