Cookie Clicker has no way to "win," so players can play for as long as they want. As a result, these strategies are geared towards making progress faster, and a casual player doesn't need to use them. But some strategies are mathematically better than others to the point where they make the other strategies useless. Being strategic is important if you want to move forwards faster or have so many cookies that they shake the universe. The game can be broken up into three main parts: the Early Game, the Middle Game, and the Late Game. With the addition of Prestige, there is even more to do after that.
The Start
In the beginning of the cookie clicker game, when you only have a few Buildings and most of your cookies come from clicking, this is called the "early game."
It is best to buy Cursors because they will be useful in the future. Check the percentage of how many cookies your buildings are making overall is a better tip. This will let you know if you should save up for a good upgrade. Use a spreadsheet to figure out how many cookies you will need for X buildings. Use this information to get about 25 Grandmas, 15 Farms, and 15 Mines, and you'll have Factories in no time.
Mid-Game
Idling comes into play here. You'll get to a point where you have a building that makes the most cookies and an upgrade that's too expensive and will take you a long time to get (actively). This can be fixed by letting the game run on its own. You can do something else to pass the time, and when you come back, you'll have a lot of cookies to spend. Make sure you get the improvement for the building that makes the most cookies. If you haven't done that yet, use your cookies to buy an upgrade for that building, then buy it. If you can't buy the upgrade, do something else for a while and then try to buy it again. You'll also get your first Kitten Upgrade. This increases the CpS multiplier by a percentage that depends on how much Milk you have, and each upgrade adds to the effect of the last one. Now is the best time to look for Achievements. Try to get the Miscellaneous Achievements, because they can get you a lot of other achievements. When you bake at least 1B cookies, you can also get Sugar Lumps. Click on the link to learn how to get all of the Sugar Lump achievements. If you've reached Shipments, you're in the Early Late Game.
Make sure to get at least 15 of each building after grandmas to be able to buy their grandma upgrades.
