A method of assembling first and second furniture elements, the first furniture element including a groove defined between first and second opposed side surfaces, the second furniture element including a tongue defining first and second opposed tongue surfaces, wherein the method includes (a) inserting the tongue into the groove so as to establish contact between the second tongue surface and the second side surface, the first side surface and the first tongue surface thereby defining an elongated compartment; (b) providing a furniture locking element having (i) an elastic base portion having first and second side walls forming a trough; and (ii) a stiff insertion portion configured for insertion into the trough; (c) inserting the base portion into the elongated compartment, forcing the second tongue surface toward the second side surface; and (d) inserting the insertion portion into the trough, forcing the first and second side walls away from each other.