I currently have two established religions within my world (with plans to add more). One based on astronony, astrology, and the veneration of stars. The other a sort of angel worship greatly inspired by Roman Catholic and Greek Orthodox Christianity. But they both feel...half-done. I have some basic tenants, doctrines, and myths. But being born and raised irreligious, I'm not entirely sure what even is missing. Whay are some tips for constructing religions? Are there any particularly good places for me to look for inspiration?