To draw molecular structures, one should: 1. Draw the Lewis structures of components and make the most electronegative atoms outer atoms, except for hydrogen. 2. Ensure outer atoms have a full outer shell of 8 electrons using single, double, or triple bonds and charges. 3. Central atoms in period 2 can have up to 8 outer electrons, and period 3 atoms can have up to 18. The VSEPR theory then predicts 3D structure by minimizing electron pair repulsion between outer shell electron pairs and lone pairs.