For example, say you are interviewed for a job. You can choose to direct them to your website where a possibly offensive philosophy is discussed, or not. If you do not, the possible future of your prospective employer seeking out your page is removed, hence the future, which is in this context the set of all possible futures, has been altered by the present.
Another example: Say you have an assignment due the next morning. With each hour you delay, the futures in which you hand in the assignment are pruned off, until at the moment of the due date, where the specific future of not handing in the assignment is choosen. Note all the decisions were made in the present, and molded & created that thing known as the future.