Here are some guideline on Harmonic Pattern Trading. These several articles can help you to improve your performance.
Quick Guideline for Harmonic Pattern Plus for Starter
Pattern Completion Interval versus Potential Reversal Zone
Tactical Use of Pattern Completion Interval (PCI)
Link to Harmonic Pattern Plus
Harmonic pattern plus is cheap but it is extremely good product for its price.
Below are the Links to Harmonic Pattern Plus
Link to Harmonic Pattern Scenario Planner
With additional features of predicting future harmonic patterns, this is very tactical harmonic pattern indicator with advanced simulation capability on top of features of harmonic pattern plus.
Below are the Links to Harmonic Pattern Scenario Planner