Always use "excuse me" if you have to get into someone else's personal space.
Someone at the store is standing in front of the shelf where there's a can you want to grab? Don't just reach into their personal space without warning, say "excuse me" or "pardon my reach" first so that they at least have a warning that someone is about to reach into their personal space, and most importantly, so that they have a chance to move before you get into their space.
Or if someone is standing on a walkway or in a doorway you need to get through, don't just silently shove past them or squeeze past them, say "excuse me" so that they have a warning that a someone is about to squeeze or shove into their personal space, and they have a chance to move out of the way before you do you.
People deserve a fair warning if someone is about to squeeze or shove or reach into their personal space. A lot of people are not okay with having someone, but especially a stranger, randomly shove or squeeze or reach into their personal space without warning. They also deserve a chance to move out of the way first for the sake of their comfort.
Try to avoid just staring at people who are in your way and expecting them to read your mind that you want them to move. Most people cannot, in fact, read minds, so having someone stand in front of them and stare at them often only leads to making them feel uncomfortable and frustrated.
But also more importantly, if you are standing somewhere someone needs to get to, and they say excuse me, you should move aside for them even if just temporarily, so they can avoid the discomfort of having to reach into your personal space or squeeze past you.
If someone is saying "excuse me" it's because they would like you to move because they don't want to have to get into your personal space, whether it's out of respect for you, or just because they themselves are not comfortable getting in your personal space.
All of this goes double for people with trauma and/or people who are neurodivergent. If someone has trauma related to abuse or assault they may find it more upsetting or possibly triggering to suddenly have someone shoving or reaching in their personal space without warning.
Or, many types of neurodivergence can make it especially disturbing and unpleasant to have someone else in your personal space, especially without warning.
You can never be 100% sure who is and isn't traumatized and/or neurodivergent, so always practice respecting other's personal space by giving them a fair warning with "excuse me" or "pardon my reach" before getting in their personal space, and moving aside when you hear those magic words. Or, even if someone isn't traumatized nor neurodivergent, it's still fair to not like someone in your personal space without warning and not being given the opportunity to move first.
