A friend reminded me of something I used to do before big races (for me), which I thought other runners might enjoy trying. That was to trim my laces so each racing step would be just a tad lighter than the step you made during training when the shoe had the full lace weight. It’d technically be lighter already because with each step, you’d wear down your shoe a bit more. That’s as long as you make sure you don’t pick up gravel and rocks in your shoes!
Now, if you had racing flats or special shoes only for races, which are lighter than your training shoes, this won’t work. I had those but not for marathons, where I took the most steps in a race. Other things could also negate your technical shoe weight reduction, of course. Maybe you weigh more or it’s a wet day so the water will make them heavier, but you should still be at a relative advantage than if you had the full lace shoes. Still, that doesn’t really matter.
The thing really you do this for is the psychological edge. To know each step is lighter than the ones you took in training, or at least optimized for the day, is an ace in your mind! Considering I believe that distance running is 90% mental, 9% physical and 1% primal every now and then when you need to dig deep, this trick covers for 99% of it for you on race day!