When picking up a signifacator

If i for instance am going to do a spread and im going to pick for instance the Fool to represent me as a significator what do i do with the card ?Do i take it out of the deck and leave on the side or do i hope it shows up doing a reading or do i just have the fool in my head while im doing a reading?

It depends on the spread you're using. Most of the time, you take it out of the deck and put it into a pre-designed position in the spread, e.g. in the Celtic Cross, the significator usually goes in the center. But, for instance, in the Opening of the Key, you actually look for it in 4 stacks of cards and then interpret the stack with the significator.

I got away from using significators in my CC spreads. One reason was I was too lazy to pull them out of the deck and would consider my significator “implied”. Then an interesting thing happened. It appears that I am represented by three Kings; Cups for my emotional side, Wands for the creative, and Swords for the authoritative, these all coming up in the Cover position more often than not, depending on the situation
One recently discovered method is to take a card, key it in as your significator, Insert back into deck, shuffle, then go through the cards until you find your significator. The cards immediately before and after are to be read.
A simple three card spread but found these to be at times, scary accurate, or at least very relevant.