Some additional tips. Two key ways to enable this are to leverage scripts that are already present in the default tenant.
1. Set "GenIsOwner" as a condition script on any workflow that requires just a single sign off and then ensure that the record owner is set to the person you want to sign off on the record. This is also very useful in controlling what items show up on people's Outstanding Work List
2. The second is the "Multi-Approval" board scripts that we included. This is a very reusable method for creating a workflow step that requires multiple people fully approve a state before moving on. Examples of how this is configured is in many workspaces today - Consider looking at the "Change Orders" workspace.
Extra Tip - This is very simple to recreate in any workflow. Simply make sure that each of the "Transitions" that are coming out of your state are named exactly as the examples (Approve, Reject, Final Approaval, Cancel) to ensure the scripts work - then on each of those transitions, set the matching script. The Cancel step is optional. The State name itself can be named anything you like.