Shape your base: Inflate a balloon or shape damp sand into a rounded form. Cover with cling wrap to prevent sticking. Mix your concrete: Combine PPC Cement with water until thick and workable( not runny). Build the nest form: Apply concrete around the mould(± 2 – 3 cm thick). Keep it uneven for a natural, organic look. Mix the concrete: Mix PPC Cement, sand, stone and water to a thick, pourable consistency( no dry patches). Create the opening: Press a small bowl or cup into the side. Adjust edges by hand to keep it imperfect.