Using your causal effect estimate, figure out how big a difference your main independent variable can make. If your main variable is dichotomous, then the only possible change on the variable is 1, so figure out how big an effect a 1-unit change has on the outcome (taking into account any interaction terms). If your main independent variable is continuous, figure out how far apart the 25th and 75th percentiles are on that variable, and figure out how big an effect would be produced by a change of that size. Out of the overall range of your dependent variable, how much can you cover with this effect?
It is often useful to use graphs to visualize the size of causal effects. Produce an attractive and professional visualization that represents the magnitude of your causal effect.
What can you do to test the assumptions behind your statistical model? Identify at least two assumptions, provide statistical tests, and explain the results.