Improvements in focused ion beam (FIB) material removal rates utilizing geometric and chemical enhancement were investigated. Geometrical optimization of FIB micromachining of Permalloy and diamond was investigated to determine the magnitude of material removal rate gains that could be attained by increasing the angle of the ion beam with respect to the sample surface normal. The combination of geometrical optimization with chemical enhancement(C2Cl4for Permalloy andH2OandXeF2for diamond) was then investigated to determine whether additional gains in material removal rate could be attained. FIB sharpening of a diamond nanoindenter tip is also presented as a practical example of diamond micromachining withH2Oas the removal rate enhancing species.