Identify the different intervals for the input variable
Write one expression for each interval
Use braces to group the expressions
State the condition for each expression
Make sure the intervals do not overlap
Make sure the intervals cover all intended values
Use open or closed endpoints as needed
Evaluate the correct expression for the given input
Substitute the input into the matching rule
Simplify the result
Graph each rule only on its interval
Mark endpoints correctly on the graph
Check continuity at interval boundaries if needed