The US open is not the starting gun for your trade. It is information. Price is looking for a balance between people who must sell and people who chased the premarket. The first minute is often the worst one to be in, precisely because it looks the most important.
Make a short list before the bell. Three names is enough. For each one: what is the catalyst, where are the premarket high and low, and how wide is the spread in dollars. If you cannot answer, the name does not stay.
For the first five minutes you only draw. Mark the opening range. If price holds above the high of that range and volume does not die immediately, then — and only then — there is a gap-and-go to look at. Volume without price follow-through is distribution, not demand.
Minutes five to fifteen are where a flag can build. A flag is a pause: lower volume, a tighter range, higher lows. A pause that falls straight through the open is not a pause. It is a rejection.
Decide before the open how many attempts you get. One is an adult answer. Two is a courtesy. Three is usually spite. When the attempts are gone, your job is to watch, not to invent a new setup so you can participate.
Close the note with one sentence: what price did, what you did, and whether that was the plan. If they differ, trust the plan next time — or the plan was too vague to follow. Both answers are useful. The feeling in your stomach is not.