Hydrazinium nitroformate (HNF), an energetic and eco-friendly oxidizer, was desensitized successfully by changing its crystal size and shape and by coating with a nanocomposite. During crystallization, various methods were tried out which include mechanical stirring, ultrasound and using crystal shape modifiers (CSMs). Experimental results showed that the multi-pronged approach to control the shape and size of the crystals by a careful choice of CSMs and crystallization method worked well to counter the preferential axial crystals growth, thus shifting the long needles to near cubical shape. Among various coating agents, a hydroxy-terminated poly butadiene (HTPB)-based clay nanocomposite was found to be most effective for reducing the friction and impact sensitivity of HNF. A Scanning Electron Microscope (SEM) coupled with Energy Dispersive Spectroscopic (EDS) analysis was found to be a very reliable and most useful technique to assess the extent of coating on HNF so as to achieve a consistent figure of insensitivity. The coating material was stable as well as compatible with the HNF crystals as revealed by thermal analysis.