Always keep the lid closed
Olive oil and air do not get along well at all. If you leave the lid open your fine and delicious olive oil will turn rancid very quickly and so what would be the point of buying a top quality product?
So always keep the lid closed (even when using at the table).
Once opened more and more air will enter, so be generous with your servings and aim to finish your open bottles within a month after opening.
Keep it away from heat and especially the oven
Olive oil is simply freshly squeezed olive juice and so needs to be kept away from heat.
Be careful not to forget your precious bottles near the oven as the heat will cook away all the delicate freshness.
You might wish to store them in the fridge, in which case your olive oil is likely to turn cloudy which is perfectly fine, simply let them come back to room temperature for a smooth look.
Hide it from light in a dark cupboard
Fine olive oil is very delicate and will lose freshness if exposed to light, for this reason good olive oil comes in a dark bottle – like wine.
Always store your olive oil bottles in a dark cupboard away from ambient light and particularly direct sunlight.