That's what my husband, the engineer, says before he starts cooking or baking. The guidelines, of course, being what most people refer to as a recipe.
The other famous first line is "I just need to modify this a little."
He never follows a recipe.
And the thing is - anything he makes always turns out great. However he seldom keeps track of his modifications, so he can never duplicate his successes. Lately though he's enlisted Pippi as his note-taker. So maybe sometime we can make something again.
Though - chances are, if we do - he'll modify his modifications.