It's difficult to spread miso on tofu since it's so soft! But if you spread the miso on kitchen paper towels, not only it is easier, you use less miso and save money plus cleanup is a snap so you get to kill three birds with one stone.
First, spread a clean dry paper towel sheet on a dry cutting board.
Squeeze some miso out on top of the paper towel (an approximate amount is ok I think).
Spread the miso into a cross pattern with the back of a spoon or something (keeping the size of the tofu in mind).
Put the tofu on top of the miso, and wrap it up so that the miso is touching the surfaces.
Put the tofu back in the plastic pack it came in, and let it rest in the refrigerator overnight.
If you want to marinate it for longer than overnight, change the paper towel with a clean sheet. No need to re-apply any more miso since it will have already penetrated into the tofu.
Story Behind this Recipe
Making salted tofu then miso tofu was too much work, so I decided to make it a lot simpler.
In Step 3, you don't need to spread the miso to the corners since it won't come into contact with the tofu; spreading it in a cross pattern is enough. Take a look at the size of the tofu and adjust the width of your spread miso accordingly. (Eyeballing it is fine.）