Before replacing the oil filter stand gasket try to tighten the bolts. I was all set to replace mine and had cleaned the area of the leak just to make it a little less messy for me. Noticed the leak was from around the bottom two bolts and one was about a full rotation loose. After this no more leak.
That one leak was costing me a quart every 400 miles and made a mess under the car. Also inspect your oil cooler lines. I had one with a very tiny hole on the bottom of the hose and when it leaked it leaked bad. Was on a 1500 mile road trip when this happened and was about 500 miles from home. Was pumping a qt. every 50 miles and oil was everywhere. However standing there with the car running you could not see where it was coming from. The oil cooler is thermostat controlled. If the engine is cold you will not have a leak from these hoses. Look at the back of your car. If your trunk lid and tail light area is full of tiny oil spots you have a leak somewhere.