After a good brain storm, hopefully you have a wealth of ideas and now it is important to sort out the best. Then you have to decide on an idea and develop it into what will be your project.
A tool that helps you sort among your ideas. Make two tables with a plus page and a minus page in each table. One table stands for facts and the other for emotions and performances. Then list all the advantages and disadvantages of your idea, both factually and emotionally and write them down in the tables.
Example: My idea is to sell "fika" (Swedish word for cookies, buns etc...) outside the school
The next step is to look at the minus pages of the tables and see if there is anything you can do to turn the negative into something positive. Then it's time to summarize and see if your idea still feels interesting to move on with.