In your opinion what does it mean to be good in bed?

Okay, every answer so far is giving you good advice... on how to become good in bed. But they're not answering the question. Lots of people who are enthusiastic and caring and willing to learn are terrible in bed, simply because they don't have enough experience yet, or they have poor body awareness, rhythm, etc.
so whats your answer to the actual question: Being good in bed?

from me the answer is split into two important factors
First, you need to be able to read your partner. This comes naturally with time (which is why sex often gets better as two people become comfortable each with other.) But some people also have a natural talent for it. Empathy helps.
The second is being able to do something about it. This is about skill, fitness, a sense of rhythm, and a bit of imagination. This can also improve with practice.
so Basically, being good in bed means being able to sense and direct the "flow" of sex in a way that feels natural and right. It has a lot of parallels with dancing, and quite a lot of the skills carry over!

some answers i got when carrying out my research include:
Balance between caring about your partner and caring about yourself. Openness to hear how you suck without getting hurt feelings. Taking suggestions without being resentful. Willingness to at least try new stuff. Keeping yourself fit and in shape. Being just generally open-minded. That's all stuff you can control.
Then there is genital compatibility and that's just luck of the draw between you and your partner.
Willingness to learn and communicate.
Wanting to please your partner. Knowing your own needs and how to express them. Attraction.
Natural chemistry.
If you're a guy all you need is lots of money and if you're a girl all you need is a vagina.

Be considerate, don't just think of yourself and your own pleasure. Communication pre sex. Have fun