In terms of Funnel Optimisation, there are two types of analysis that all store owners should perform:
The purchase funnel measures the actions your customers take before making a purchase. Completing purchase funnel analysis helps you identify areas for improvement, like low resolution images, poor product descriptions, unclear pricing or even website errors.
Checkout funnel analysis will help you pinpoint when and where your customers leave during the checkout process.
Google Analytics is helpful for doing funnel analysis. If you are not currently using Google Analytics to do funnel analysis, I suggest you checkout the below video from KISSMetrics.