Two approaches, neither simply right
Most heists offer a quiet or loud route. Quiet preparation takes longer and forgives fewer mistakes. Loud execution is simpler but needs better gunmen.

Heists distinguish GTA V from the rest of the series. Before most heists, you choose an approach and crew. That determines how much you take and whether anyone dies.
Most heists offer a quiet or loud route. Quiet preparation takes longer and forgives fewer mistakes. Loud execution is simpler but needs better gunmen.
Each crew member takes a share. An experienced driver or hacker costs more but completes the job. A cheap hacker gives less time, losing more than their lower cut saves.
Anyone who survives returns with more experience and a higher cut. Keeping the same crew pays because usefulness rises faster than their percentage.
Cars, clothing and weapons acquired beforehand are genuinely used. Damage the getaway car during preparation and you drive what remains.
In the order they appear
A training heist that teaches the system. The quiet route requires gas from a laboratory and masks; the loud route only requires breaking in. The earnings differ noticeably, showing that preparation pays.
Choose the cheapest driver. Escape speed matters little here, so the lower cut is useful.
The only heist that yields nothing. This is deliberate: a story turning point, not a source of income. Players have not made a mistake.
Do not try to optimise it. The take is zero regardless of the approach.
An open bank robbery in a small town. There is no quiet route: it is a firefight from beginning to end, including the retreat through town.
Do not economise on gunmen here. A weak gunman means collecting ammunition during the firefight.
Two entirely different missions. The roof route is action-focused and uses parachutes. The fire-crew route is slower, quieter and played in disguise inside the building.
Both are worthwhile. Their content differs more than any other pair of heist approaches.
The climax and largest take. The subtle route uses a tunnel and swapped vehicles; the obvious route is a frontal attack with armoured cars. The reward far exceeds everything before it.
The most expensive crew finally pays here. Their percentage is higher, but it is calculated from a much larger base.
Heists appear to be the main source of income. They are not: the stock market pays more, and the game never explains this.
Lester orders five assassinations. Each lowers one company's shares and raises a competitor's. Buying the competitor before the assassination and selling afterwards earns far more than any heist.
The decisive rule: save these missions until the end, when you have money from The Big Score. Investing a million yields much more than a few thousand, and the game offers no second chance.
The stock market works differently in the story campaign and GTA Online. This method is unavailable in Online mode.
Seven collections spread across the map, from letter scraps to spaceship parts. Each entry explains its reward.