One of your assumptions is that magic comes from the gods. So the way to use magic might be to understand something of how a particular god thinks and use that as the starting point for a spell.

For example: The Prishtu god of honey and hospitality, Delgoran, is worshipped a mountain where a particular blue flower grows. Because Delgoran has an affinity for the flower, it can be used in a number of rituals and spells that provide comfort and shelter for people. In its simplest form, a common worshipper can hang a bundle of the flowers over their door to summon bees to fertilize their crops, but a portion of the yield must always be given away, preferably to a stranger or a cleric. A priest of Delgoran might use the flowers to make incense that creates a sense of peace and fellowship in everyone who breathes it. A magician might use the flowers' nectar in a potion that causes people to offer aid to the traveler who imbibes it. Herbalists also recommend an ointment made from moisture squeezed from the flower's stem as a treatment for bee stings.

I have a feeling I could really run with that!