In our perfect world, we establish this boot up sequence and are able to do it every single day. But sometimes life gets in the way or something random throws you out of your routine. The point is that we need a way to execute despite imperfect circumstances. Enter my three fifths rule. If you aren't able to execute your full ideal boot up sequence, simply aim to nail three out of the five senses of the sequence.
The Boot Up Sequence is a fixed set of actions and environmental cues that mentally and physically mark the start of your work session. While it can be used for any work session, I find it particularly impactful and valuable in priming for a deep work session (daily focused work on the "most important thing").
The Boot Up Sequence is built around the five senses: Touch, Taste, Sight, Sound, and Smell. Engaging each of these allows you to quickly and consistently enter your flow.
If you aren't able to execute your full, ideal Boot Up Sequence, simply aim to nail 3 out of the 5 senses of the sequence. My experience suggests that 3 out of 5 is achievable under a variety of circumstances, and it's enough to create the mental and physical entryway into your flow.