Setting up your SRS decks for sentences can make or break progress. While there's really no "wrong" way to set up a deck, there are plenty of "right" ways to. Let's begin with an example of how my sentence decks (yes, as in multiple - I'll get to that later) are set up, starting with a card sample.
Front of the card:
Back of the card:
にほん は（わ） はじめて です か。 Japan (topic) first time it is ? Is this your first time in Japan?
Basically, the front of the card contains the sentence in Kanji while the back contains a few elements to aid in learning it. First, the sentence is re-written in hiragana (sometimes containing katakana if necessary). Second, each word's "definition" (in this case, in English) is listed out in the same order as the hiragana sentence above it. I've also made note of the particle's role in the sentence. Last, an English "translation" is listed. I say "translation" because it is really more of an interpretation based on the contents of the sentence.
I should note that this format is for those just beginning their journey. Later, once you've got a better grasp on vocabulary, the English "translations" should be omitted, and replaced with Japanese definitions.
Why multiple decks?This is really more of a preference of mine, but I prefer to keep my decks sorted by casual vs. "polite" sentences. I do this so I can mentally separate the two. I'd imagine at some point, these may merge, but for now it helps me keep this in the back of my mind without having to enter a "politeness level" on each card.
For now this actually means that I have 3 decks, though the third is not very full since entries in that deck can be/are considered rude.