(especially of beliefs or behaviour) generally accepted or approved of; following generally accepted beliefs (Oxford)
following closely the traditional beliefs and practices of a religion (Oxford)
(of beliefs, ideas, or activities) considered traditional, normal, and acceptable by most people (Cambridge)
He is very orthodox in his views. (Oxford)
We would prefer a more orthodox approach/solution to the problem. (Cambridge)
orthodox views
orthodox approach
Conservative
Conventional
Untraditional
Unorthodox
Orthodox