How can you tell if there's mutual attraction?

Ok can someone help me out here?

How do you know when two people both find people attractive?

I actually have a pretty good sense IMO but sometimes I can't tell if the other person is really interested. What I've learned as I've gotten older as well is that just because y'all are vibing it doesn't mean the other person wants to take it past that which is often the answer to questions like "Why didn't he ask me out?" "Why does he flirt but not take my number?" They likely are fine with JUST flirting and don't want to escalate.

But my signs are:

- Awkward tension or vibes (awkward because of attraction)

- Catching eyes (catching them look at you out of periphery, or meeting each others eyes naturally)

-Having them look you up and down or vice versa

- Them being extra nice or attentive towards you

What has been others experience?