Another important factor, which is always worth thinking about, is how sweet the e-liquid you are using is. The sweeter the e-liquid is, the more likely it will be that it will contain natural or artificial sweeteners. The sweeteners with the e-liquid may caramelise on the coil within your tank which gives a similar issue to burning out the coil. Due to the caramelised e-liquid on the coil, the cotton wicking material cannot be saturated correctly and the coil tends heats up and gives you a burnt taste. To fix this issue you would need to change your coil more regularly to keep the best possible performance.
I would also take note, that some e-liquids are very sweet and can sometimes burn out a coil within a few (2 or 3) days compared to the normal lifespan of a coil (7 - 10 days). Depending on the amount of usage and the power of the device you are using can both factor into the shortening of the coils life with these sweeter e-liquids. Unfortunately, no matter how well you think you have looked after the coil, this will happen and there isn’t really a way to get around it happening.