Choosing a comforter that suits you perfectly is all about finding the right level of warmth. Nobody wants a comforter to be too hot or too cold.
What the temperature is and what kind of warmth you are looking for should be the biggest consideration when determining the type of comforter you need.
Comforter weights are normally referred to as lightweight or heavyweight or referred to by their seasons, e.g summer or fall.
However some people will be better suited to a lightweight comforter even in winter and others would prefer a winter comforter for summer. Or perhaps you would choose a medium comforter and stick with it year round. It all depends on the individual.
The first thing to consider is what your general body temperature normally is. Are you the kind of person who often overheats? Or are you one who really feels the cold? When you go to sleep do you tend to overheat or do you tend to wake up because you are too cold?
Obviously if you tend to feel the cold you should be looking towards a heavier comforter. Likewise if you have a habit of overheating like an old car you need to look towards a lighter comforter.
Also consider the general temperature of your bedroom. Do you open the windows at night? Do you use a heater or an air conditioner?
An organic wool comforter is the best option regarding temperature and breathability. It is the most effective insulator of all natural fibers and can keep you cool when it's hot and warm when it's cold.
If you sleep alone then choosing a comforter is a much simpler process. Figure out what works for you and then you're away. But those who spend their nights next to their dearly beloved need to take both people's needs into consideration.
When you sleep next to someone you will generate more body heat than if you slept on your own. And your partner will generate more body heat than they would if they were on their own. So you have more than just two people's body heat. Keep this in mind when choosing a comforter. If you go for something too heavy you might very well be too hot.
If you intend to sleep with a comforter and only a comforter then you will need to be looking at a heavier option. But if you want to use other blankets that you already have then you could get away with a lighter comforter.
Any blankets you decide to use with your comforter should also be organic. They might not be directly touching your skin but they will release residues from the chemicals used in processing into the air.