Great question and I don't profess to be an EWT guru -- I only use it when I see obvious patterns as opposed to others who try to label every iteration. If I see patterns that fit with the market structure I'm seeing, I'll call them out.
I think the identification of a wave is also dependent on my view of all the other tools that I use such as measured moves, fib levels and various momentum / oscillator indicators. So in real-time, for instance, I could see the NQ pullback after hours / pre-market hitting levels where my momentum indicators suggested we should find support so it led me to believe that was setting us up for that wave 5 up today. Also, once I saw that wave 5 was breaking into another wave 5, then I could also see that this move up was about done. So I'm looking for various levels to come into play as this market pulls back and I may not know for sure whether those levels will hold or not -- sometimes I just buy and trail and I end up being proved wrong. Does that make any sense? In the end, I'm just trying to find an edge and reduce the downside. I'm not perfect. Also, some intuition comes into play but that comes from experience.
Happy to talk more on this in PMs, etc.