As a Roman catholic, we observe Ash Wednesday which marks the start of the lenten season. The priest or any church minister rubs the sign of the cross with ashes on the forehead of any one who wish to have it. From this day, fasting and other form of sacrifices are done in observing the Lenten Season. I believe that Lutherans, Methodists, Presbyterian denominations aside from catholics observe Ash Wednesday, I don't know how but maybe just the same with catholics. If there's difference, it won't matter as long as it's done with purpose and that's to remember that you are dust and to dust you shall return.