Garlic oil can be a hazard! Storing garlic in oil is not safe --
botulism! Throw it out!!!! (and check with your local health
department or USDA about garlic in oil)

The oil I make and use most often is made with cleaned and then dried
rosemary springs, which I poke into a smallish bottle of very good
olive oil. I add a few whole peppercorns, too. Shelf life for that
oil seems very good, and I make enough to last until the following
year. Another very nice oil to make is olive oil with cleaned, dried
lemon peels (only the zest part -- no white pith!) That is a wonderful
oil for salad dressings, and seems to have at least a year of shelf
life, too.