Blend together softened butter and margarine until smooth.
Cream with sugars.
Add eggs and vanilla and beat well.
In a separate bowl, mix the flour, baking soda, and salt.
Add to the creamed ingredients and mix well.
Fold in chocolate chips and nuts.
Note: If you have a "squeeze trigger" type of ice cream scoop, use this to scoop cookie dough onto ungreased cookie sheets. This will insure that the cookies are uniform in size, and prevent some from being over-baked, and some from being under-baked.
Do not crowd; allow at least 2 inches between each cookie. Bake in a 350 degree oven for 10-12 minutes.
Note: It is very important not to over-bake. The cookies should be lightly golden brown, but not shiny on top.
This dough will keep nicely in the refrigerator for two weeks enabling you to make just one dozen at a time if you like.