Following this question about not asking leading questions, I tried to apply the advice in my day to day life for all kind of situation (including online conversation).
However, I find that I am now asking awfully vague questions, the kind of questions you would ask if you hadn't been listening to what the other person previously said.
For example, let's assume that one of your friends participate in a festival at the weekend.
The non-leading question would be:
Hey, how was the festival?
But then, if you know that such an event could make your friend terrible tired, you would also like to inquire specifically about that. For example:
Wasn't it too tiring?
But this is a leading question, which means that your friend might feel pressure to answer in a certain way, which is less likely to happen if you ask a non-leading question (like, when someone asks "did you understand?" you feel pressure to say "yes" even though it's not the truth).
So, you could say instead:
How is your tiredness level?
But, honestly, this is the kind of question your doctor might ask and, as a friend, I would feel weird asking that (at least in the cultural context of France).
So, assuming it's possible, how can one ask non-leading questions without sounding (too) cold/detach?
Note and clarifications
Asking about the festival is fine, even if it can be a bit vague. And, as someone with tiredness issue, I know I mostly never talk about how something made me tired unless someone specifically asks. In those case, I'm happy that the person asks but it doesn't mean that I will not be tempted to undermine the truth (in order to "protect" the other person from the truth).
The example above is mostly a real example. But it was an online, asynchronous, conversation where I decided to ask "Hey, how was the festival? Not too tiring?" in a single message.