For a lot of SMBs, I usually rely purely on contenting filtering and IPS and allow all traffic.
For large companies I might only alow HTTP and HTTPS from everything internal, and then only named hosts (such as AD controllers) being allowed to send DNS queries. I have some customers that are only allowed to access specific named web sites and nothing else.
For manufacturing companies, there might be entire networks with zero access to the Internet.
You'll have to give consideration to your security posture and risk, and then decide what is apropriate.