Best Practices:

The document signer must be PHYSICALLY PRESENT before the notary.*
An essential element of the notarial act is personal, face-to-face communication between the document signer and the notary. This is necessary for the notary to assess the signer’s comprehension of the transaction and willingness to sign, to help ensure that neither coercion nor fraud are present. Physical presence of the signer is so important that notaries who fail to require it can be charged with a crime and punished.

The signer must be PERSONALLY KNOWN to the notary or must produce SATISFACTORY EVIDENCE OF IDENTIFICATION.*
One of the notary’s main responsibilities is to determine, beyond all reasonable doubt, that the person who has come for a notarial act is the same person named in the document as the signer. The signer must either be personally known to the notary (regular interaction over time has given the notary a deep-seated belief in the person’s identity); or the signer must present satisfactory evidence of identification, such as a state-issued driver’s license. The documents that a notary may accept as satisfactory evidence of identification vary by state but all states allow a current driver’s license. Some states also allow use of one or two credible witnesses to vouch for the identify of a signer, subject to the credible witness(es) ability to truthfully swear to a series of statements about the signer.

The notary must be presented with an ORIGINAL document.*
An original document is one that is unsigned, or that was/is physically signed in “wet ink” by the document signer. For example, an unsigned document may be faxed and subsequently signed by the document signer. That faxed document, with its original wet-ink signature, is an original document. A document that was previously signed, then faxed, is NOT an original document. It displays a facsimile signature, not a signature stroked directly onto the paper in wet ink.
Documents requiring an oath must be signed in the notary’s presence.

The document presented for notarization must be COMPLETE.
The notary cannot perform a notarial act over a document that is missing pages, or contains blanks that should be filled-in prior to the notarial act. If missing pages cannot be presented to the notary, or if the signer does not know how to deal with the blanks in the document, the notary cannot proceed. (Note: some blanks are clearly intended to be filled-in later, such as “Office Use Only” blanks. These are acceptable at the time of notarization.)

The DOCUMENT DATE must be the same day as the notarization or earlier, but NEVER later than the day of notarization.
When the document to be notarized is a dated one, then it must be dated the same day as notarization or earlier. The purpose of notarization is so the formalities of document execution are conducted before a notary. The notary then records the facts of the document execution in his/her notarial certificate (the part of the document that the notary signs and seals). Notarization is the final step in document execution, so it cannot occur before the document’s date. It is possible for a signer to present an undated document for notarization; i.e., a document that does not require a date or display a blank for a date to be filled-in. If the signer does not wish to date the document, the notary may proceed with notarization, but should carefully note in his/her journal that the notarial act was performed on an undated document.

The document must display NOTARIAL LANGUAGE that clearly indicates the desired notarial act.
This is the notary’s primary means of determining the required notarial act. Look at the notarial certificate. Check the format. Does it comply with state law? You also want to look for the specific wording; sworn (or affirmed) or acknowledged. These words tell you which notarial act is required - whether you have to administer an oath (or affirmation) or take an acknowledgment. If the document signer insists on a notarial act but no act is clearly indicated on the document, the signer or other party involved with the document must choose the notarial act. The notary can explain the differences between the various acts, but cannot choose the act or he/she risks practicing law without a license. If the notary feels the document does not require or the only reason a notarization is being asked for is to add legitimacy to a document, the notary must refuse to continue.

The notary must feel assured that THE SIGNER COMPREHENDS the underlying transaction and is PROCEEDING WILLINGLY.
Notaries provide an invaluable service by assessing a signer’s comprehension and willingness. It is not uncommon for signers to execute a document under duress or coercion. Sometimes signers don’t really understand why they are executing a document. It’s up to the notary to recognize when a signer suffers from coercion, misgivings or inability to understand the transaction, and to stop the notarial act if necessary.

The notary must/should complete a journal entry.*
Many states require the notary to keep a notary journal of all notarial acts. States that do not require a notary to keep a record of his or her notarial acts strongly recommend that the notary keep a journal. Keeping a notary journal is for your own protection and for the protection of the public and your employer. The journal entry should contain information about the signer including his or her original signature, the title and date of the document, the notarial act performed, the method of identifying the signer, and any unusual circumstances associated with the notarization.

The verbal ceremony must be performed.
Here's the essence of the notarization.
In the case of a document requiring an acknowledgment, the verbal ceremony is the question that officially determines the client’s understanding of the document and willingness to sign the document. In the case of a document requiring an oath or affirmation, the verbal ceremony is the official question that causes the client to swear or affirm that the information in the document is the truth. It is called a “verbal” ceremony because the question must be asked aloud by the notary and the client must make a verbal response that the notary can clearly hear.

A completed notarial certificate is required.
This certificate is the notarial wording or language which records and describes the events of the process of performing the notarial act. The wording may be printed on the document following the signer's signature, or it may be on a separate attached form, known as a "loose notarial certificate." Without a completed notarial certificate, the notarization is incomplete and be open to legal challenge.

*RON's (remote online notarizations) require specialized adaptations.