The performance of a Visualforce page is a key factor to consider in development because performance is a reason that effects the end user's satisfaction of the application. The following are the best practices to improve Visualforce's performance:
<apex:form>tag per Visualforce page because each
<apex:form>tag adds a view state to the page. A Visualforce page has a limit for view state size that is 135 KB. We can decrease the loading time of a Visualforce page by reducing the view state size.