Here are some precisions concerning the passive voice and some of its more elaborated uses!

When using the future:
En utilisant le future:

Subject + Future tense (will / is going to) + be + past participle
Sujet + Forme du futur (will / is going to) + be + participle passé.

James will / is going to write a letter.
A letter will / is going to be written.

When using a modal verb
(would / will, can / could should / shall, may, must…)

Lorsque l’on utilise un verbe de modalité:
Subject + modal verb + be+ Past participle
Sujet + verbe de modalité + be + participe Passé

Active : I will eat burgers.
Tom can beat them.
My cat must kill mice.

Passive: Burgers will be eaten.
they can be beaten by them.
mice must be killed by my cat.

With an obligating structure: to have to / ought to:
Avec la forme d’obligation:
Subject + obligation form + be+ Past participle
Sujet + forme d'obligation + be + participe Passé
Tom has to / ought to tell him.
He has to / ought to be told by Tom.

General remark: After using a modal verb – in an active sentence – there will always be an infinitive verbal form, meaning a verb which is not conjugated.
Remarque générale: Après l’emploi d’un verbe de modalité – dans une phrase active, on trouvera toujours une forme infinitive, c'est-à-dire une forme non conjuguée du verbe.
When using other tenses:
En utilisant d’autres temps:

Passive Sentences with two objects
Des phrases au passif avec 2 objets

Rewriting an active sentence with two objects in passive voice means that one of the two objects becomes the subject, the other one remains an object. Which object to transform into a subject depends on what you want to put the focus on.
Récrire une phrase active avec deux sujets  au passif signifie que l’un des deux objets devient le sujet, et l’autre reste l’objet. L’utilisation de l’un des deux objets en sujet va dépendre de ce sur quoi on souhaite insister.

As you can see in the examples, adding by Rita does not sound very elegant. That’s why it is usually dropped.
Comme on peut le voir dans l’exemple, rajouter Rita n’est pas très elegant, c’est pour cela qu’on le laisse généralement tomber.

Personal and Impersonal Passive
Passif personnel et impersonnel

Personal Passive simply means that the object of the active sentence becomes the subject of the passive sentence. So every verb that needs an object (transitive verb) can form a personal passive.
Le passif personnel veut simplement dire que l’objet de la phrase active devient le sujet de la phrase passive. De ce fait, tout verbe qui a besoin d’un verbe (transitif)  peut former une forme passive personnelle.

They build houses.
Houses are built.

Verbs without an object (intransitive verb) normally cannot form a personal passive sentence (as there is no object that can become the subject of the passive sentence). If you want to use an intransitive verb in passive voice, you need an impersonal construction – therefore this passive is called Impersonal Passive.
Des verbes qui n’ont pas d’objet (verbe intransitive) ne peuvent normalement pas former de phrase passive (puisqu’il n’y a pas d’objet qui peut devenir le sujet de la phrase passive). Si on veut utiliser un verbe intransitif au passif, il faut une construction impersonnelle – de ce fait, le passif employé est appelé le passif impersonnel.

He says.
It is said.

Impersonal Passive is not as common in English as in some other languages (e.g. German, Latin). In English, Impersonal Passive is only possible with verbs of perception (e. g. say, think, know).
Le passif impersonnel n’est pas aussi commun en Anglais que dans d’autres langues. (Allemand ou Latin). En anglais, ce passif impersonnel n’est seulement possible qu’avec des verbes de perception (dire, penser, savoir…)

They say that women live longer than men.
It is said that women live longer than men.

Although Impersonal Passive is possible here, Personal Passive is more common.
Même si le passif impersonnel est possible ici, on emploiera plus facilement le passif personnel.

The subject of the subordinate clause (women) goes to the beginning of the sentence; the verb of perception is put into passive voice. The rest of the sentence is added using an infinitive construction with 'to' (certain auxiliary verbs and that are dropped).
Le sujet de la subordonnée (women) est envoyé au début de la phrase le verbe de perception est mis au passif. Le reste de la phrase est ajouté en utilisant un infinitif avec ‘to’. (Certains auxiliaires et ‘that’ sont omis)

They say that women live longer than men.
Women are said to live longer than men.