I don't think there is one best practice and certainly not one configuration template. It depends a lot on the needs of who you are setting it up for and what you have available for set up. Managing expectations of the customer is a huge one.
I also recommend that for most ACD deployments they use a call center manager who can monitor the queue in Contact Center so they will understand call volume and will know when to have agents available and when they can take breaks. I tell them that I can make sure the calls are coming in, but I can't tell you about your customers or make agents finish calls faster.
I've seen ACD's queue up calls 40-50 callers deep and have been asked how to get more calls answered. There are a ton of answers and most come with cost or training. Agents can finish calls faster and take more calls. You can hire more agents. You can have an IVR. You can interflow to a voicemail box. You can be open for more hours. Some of those are on the customer, some of those we can help with on the phone side but there is a licensing and programming cost.
