Coconut oil swap: Melted butter works well.
Honey: Maple syrup or agave works.
Vegan: Replace the eggs with a flax egg or a pre-formulated egg replacer. I like the Energ-y brand.
Leftovers: Store muffins in an airtight container at room temperature for 4-5 days or refrigerate for up to 10 days (cool completely first). To freeze, place the muffins in a ziplock bag and freeze for up to 6 months.