Concrete shrinks as it cures. That's not a defect, it's chemistry, and it means every slab develops cracks. The only real question is whether those cracks follow a line somebody cut on purpose or wander across the middle of your patio.
The base does most of the work. Concrete is strong in compression and weak in tension, so a slab that's evenly supported underneath stays whole and a slab with a soft spot under it bends and breaks. We strip the topsoil, bring in crushed stone, and compact it in lifts. Skipping compaction is the cheapest corner to cut on a pour and the one that shows up fastest.
Slope is the second thing, and it's settled before the forms are set. A patio against the house needs to fall away from the foundation — roughly a quarter inch per foot is the working number. Get this wrong and the slab is a funnel aimed at your crawlspace. Water that sits on a slab in winter also gets into surface pores, freezes, and spalls the finish off.
Then come the control joints. These are the saw cuts that give the slab a weak line to crack along, and they need to be cut while the concrete is still green — generally within the first day, depending on weather. Cut too late and the slab has already chosen its own crack. Spacing follows thickness: for a four-inch residential slab, joints every eight to ten feet in both directions is the usual rule, laid out so the panels stay roughly square.
Reinforcement doesn't prevent cracking. Rebar and fiber hold the two sides of a crack together so it stays tight and level instead of opening up and creating a trip edge. That's a real benefit, but it's a different job from preventing the crack in the first place.
Finish is the last decision and the only one that's purely aesthetic. Broom finish gives you grip and hides a lot. Smooth trowel looks sharp and gets slick wet. Stamped and exposed aggregate cost more and look like more. All four last the same amount of time if the base underneath them was done right.