Thoroughly research your topic. Make an educated guess about how things will work.
Write a statement that can be tested based on your experiment. For example, "If I put soap in the water and then stir it, bubbles will form."
Ensure that the hypothesis contains variables. The variables in the aforementioned sentence are the water, soap and bubbles. The water and soap are the dependent variable, because they don't change. The bubbles are the dependent variable because they have been formed into bubbles from the combination of the independent variables.
Check to see if the hypothesis follow the information that you have included in your research paper. If it does not, you will need to either re-write the hypothesis, or rewrite the content of your paper and conduct the experiment to include the answer to the hypothesis.