Preheat oven to 400°F.
In a medium bowl add margarine, shortening, sugars, eggs and vanilla. Mix well.
In a separate, combine the flour, salt and baking soda.
Slowly mix by hand a 1/3 of the flour mixture into the wet ingredients.
Add the remaining flour and mix well.
Add in the chocolate chips and pecans if using.
Scoop dough with tbsp into a ball and place on ungreased cookie sheet.
Bake at 400°F for 10 minutes or until just starting to turn brown.
Let cook on cookie sheet for 1 minute, then transfer to wire rack.
Keep the cookie dough in the refrigerator in between batches.
Store in a sealed container.