One strategy I've seen recommended is to ramble a bit, including potential conversation starters on topics which are more interesting to you as part of the ramble.
For example, let's say you're talking with someone you just met in the laundry room of your apartment building. You're talking about the weather, or something similar. You want to see if this person is interested in cooking, so as you load some clothes you casually mention how you made a mess of your shirt last time you cooked to see if they bite.
I have not tried this myself, but it seems very general and subtle enough that it's not out of the ordinary.
In my experience, most socially inclined people do something like this, possibly unintentionally. So also listen to see if the other person is doing this, and if they are, be ready to pick up on anything interesting they say. Don't assume that if they mention something in passing that they are only slightly interested.
This thread is for asking the rationalist community for practical advice. It's inspired by the stupid questions series, but with an explicit focus on instrumental rationality.
Questions ranging from easy ("this is probably trivial for half the people on this site") to hard ("maybe someone here has a good answer, but probably not") are welcome. However, please stick to problems that you actually face or anticipate facing soon, not hypotheticals.
As with the stupid questions thread, don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better, and please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.
(See also the Boring Advice Repository)