There isn't really a 'proper' method for connecting two switch stacks together.
My suggestion is to use at least two links across both switches in the stack and aggregate them into a port-channel.
However, please ensure you read the release notes for your switch version. There are some known issues around cross stack port-channel. Eg.
Cross-stack LACP bundles experiencing a switch reboot will cause the remaining online port to experience an outage of up to 30 seconds. The same is seen again when the switch comes back online (present since MS 10)
@Aztec_Ninja you could connect them together with two cables, a 10Gb in the SFP+ ports and a 1Gb in the normal RJ-45 ports. The switches will shut the 1Gb link unless the 10Gb one goes down. We have used this option many times when we haven't had two spare SFP+ ports.