Map quality can be improved by avoiding altitudes above geographical areas, making sure you can map all objects of interest even if they are far distance. Moreover, it can be improved if you have the right angle of the sun and avoid lens distortion. Some other notable tricks include capturing enough overlap, using GCPs for extra quality, and choosing the right software for your needs.  Finally, ensure that your mapping drone supports autonomous flight capability, long maximum flight time, top-notch (4K) camera, RTK compatibility, good propellers, long-range transmitter, efficient gimbal, enough payload capacity, and of course, last but not least, good price for its specifics.