It is impossible to guarantee no cracks will appear in new concrete, however you can take steps to avoid it:
Ensure you use the right amount of water. Too much and as the concrete cures and dries, it will shrink and crack. Too little and the concrete cure too quickly, or not properly, resulting in cracks.
Ensure you use the correct type and strength of concrete - the team at EasyMix will be happy to advise if you’re unsure.
Do not pour concrete on frozen ground or snow, as the group will move as it thaws which could cause cracks.
Ensure adequate control joints are installed to allow the concrete to shrink and expand with the weather.