In most instances scaling a recipe down from feeding four or six to two is simply a matter of dividing by two or three, but there are exceptions.

When sauteeing, you always need enough oil (or butter or other fat) to coat the bottom of the skillet. If a recipe for four calls for two tablespoons of olive oil in a large skillet, you will still need two tablespoons of oil in a large skillet, even if you're cooking half as much fish or chicken. Don't worry about additional fat (unless you're making a pan sauce) because whatever you're sautéing won't absorb any more fat than it would anyway. And to minimize the absorption of oil make sure it's hot. In a saute the oil should be shimmering and you should see a bit of steam rising off of it.

Note: If you're making a pan sauce use a paper towel to blot up some of the excess oil before making the sauce.