If characterization daunts you, you can achieve decent results with minor characters by mixing and matching faith and works. Tolkien likes that, so you get an elf with a bow and a dwarf with an ax. Pullman doesn't bother; the only way you can tell his little insect-riding people apart is to remember their sex. The witches are even tougher to tell apart, since they're all female. He has a human kid who should have a distinct personality since he's the heroine's best friend, but he just stays some kid through all three books.
I wonder if some writers are bad at characterization because they're bad at thinking about people... not to slam Pullman for this, but if you're someone who thinks all women truck drivers are macho lesbians, how interesting can your characters be? And that's even a case of mixed "faith" and "works"!