To think ahead means to consider or think about the consequences of your actions. It means to be prepared for all possible outcomes and plan your decisions based upon the results you hope to achieve.
Ex: The sport of mountain biking can be dangerous. New riders should think ahead by wearing a helmet and making sure the tires are filled with air to prevent an accident or injury.
Ex: Since college education is getting more and more costly, many parents think ahead and start a savings account for their children while they are still very young.
To think ahead means to think about something long before it occurs. However, to think fast means to think quickly about something that requires an immediate action or decision.
Ex: Sammy was practicing baseball with his dad in the front yard. His dad threw the ball in his direction and told him to think fast so he could catch the ball before it hit the ground.
Ex: If you are travelling on the underground in a big city like London or Paris, you have to think fast. When the train comes, the doors close quickly, and you could miss the train.
To map out something means to create a plan for what you will do or see. You can map out a variety of things, such as the details of a trip or the events of a future vacation.
Ex: If you want to be successful in any job, you should map out your daily tasks. That way you won't forget to achieve all your targets for that day.
Ex: Before you map out your plans for the day, you should check the weather report. I heard that rain is forecast for this afternoon.
When you want to plan or map out the specifics of an event or situation, you create a game plan. This phrase does not just apply to games. You can create a game plan for any situation from a wedding to a business proposal to a new client.
Ex: Jules is the fun one and the natural leader in our group of friends. Before the weekend begins, we always ask her what the game plan is for Saturday and Sunday.
Ex: As a new sales associate for the paper company, I have to create a strong game plan if I want to be successful. There is a lot of competition, so we all have to be prepared.