Who is us?
It's impossible to tell about decision process. It's not a strict strategy. The only solid point is MM and getting out plan. I don't belive in strategies that say if "a" happenes than You do "b".
I look for important levels. Than after that i try to scalp between them using PA, SD, ZL (whatever it is
). ALWAYS KEEPING IN MIND HIGHER FRAMES.
I enter the trade everytime there are even few pips to be made. If price is not going my way almost instantly I just get out. One thing that i've learned during my time trading it that if it's not going Your way than it's going the other way. Staying in just makes You hope.
If You're asking about the trigger point i just wait for something that i know to happen and i just enter. Sometimes it's price struggling to go over the level. Sometimes it's a retest of a level. Sometimes i just enter with limit because i know that it's high probability and i want the best price that i can get. Sometimes it's a PA pattern.
Hope that answers Your question.