Also—if
not in Open, the red lightning strikes can be quite useful for proving their directions to be wrong. Very occasionally a lucky strike while facing correctly can reveal a Titan silhouette, but otherwise you know at least that some direction must contain a lightning-blocking Titan!
Yet once I was close enough I saw so many target blips that I could not tell in time what to target and shoot at with the torpedoes.
Listen carefully! There are eight vents which open only occasionally, where the heat build-up and vents opening is something you can hear very clearly, now at a non-Taranis Titan of course. The vents are on the front face of the Titan—that is, on the same side as the maw—positioned all around its outer edges.
If you can remain cold enough, you should be able to wait close to the Titan but not too close to the maw, and just listen to its heat-venting cycle. Once you know
when to look for targets, you should then be able to see those vents emitting yellow and they will have a grey target marker each.