Have the querent shuffle the deck while thinking about the question.
Have the querent place the deck face down on the table.
Using their left hand, have the querent lift 1/3 of the deck off the top of the stack and place it, still face down, to one side.
Using their left hand, have the querent lift about 1/2 of the remaining cards off the top of the stack, and place it, still face down, to the other side.
You, as reader, turn the piles over and observe the cards.
The pile to the querent's left is the 'past' pile. Observe what card is on the bottom of that pile
The pile in the middle is the 'present' pile. Observe what card is on the bottom of that pile.
The pile to the querent's right is the 'future' pile. Observe what card is on the bottom of that pile.
These three cards give you a quick past/present/future view of the querent's issue.
Have the querent place the three piles together into one stack.
Observe the order so that you know which of the three piles is at the top of the stack. You will be dealing your spread starting with those top cards
If the 'past' pile is on top, your reading is going to be heavily influenced by the querent's past.
If the 'present' pile is on top your reading is going to be heavily influenced by what is going on right now for the querent
If the 'future' pile is on top, your reading is going to be heavily influenced by what is coming in the future for the querent.
Now you pick up the stack of cards and deal and read your spread as usual. The preliminary cutting of the deck has simply given you extra information that will help you understand what the cards are trying to say.