I’d say 99% of my flights are based off real-world. I also enjoy emulating real-time flights. Most times, I am usually off by a few minutes (just so I can see where and how the aircraft taxis, departs, lands, etc using FR24).
A good friend of mine was flying UA768 last summer from SFO-BOS on a 772. I figured it’d be awesome to mimic his exact same flight. This time, I tuned into ATC and followed the flight in real time +/- a few second delay. Probably my most successful attempt at a realistic flight. I followed the flight as much as I could on FR24 and LiveATC until I no longer could (during cruise), but tuned back in during approach. ‘Twas a ton of fun! I was slightly inaccurate but it’s still impressive nonetheless.
Lately though, because this takes a lot of effort and time, I don’t prefer to sit around listening for ATC so I do this on an occasional basis.
(colored lines represent FR24 KML data; white lines represent my KML data).