rabbitmq – how many connections to a AMQP can one application have?

I’ve read some official material on the differences of channels from connections:
www.rabbitmq.com/connections.html
www.rabbitmq.com/channels.html
It says that channels should be divided per thread application. But I didn’t find any information about how and how many connections there should be.

After searching the forum a bit, I came across one answer that said that applications often need only one connection to AMQP. But how do I know when it’s time to increase the number of connections for an application? Because besides increasing the number of connections, I can increase the number of channels per connection (www.rabbitmq.com/channels.html#channel-max). When should I increase the channel limit per connection and when should I increase the number of connections?