blocking and tackling(The basic, fundamental skills, tasks, or roles necessary to the function of something. Used especially in business, it is a reference to American football in which blockers and tacklers have the least glamorous positions but are critically important to the team as a whole. oshkindt)
lose one's touch(No longer be able to do or handle something skillfully. For example, I used to make beautiful cakes but I seem to have lost my touch george serebryakov)
