Assume that you have created the list using custom list
template. By click on the “Customize Form” in the list settings you can
customize the list in the infopath.
Steps:
Create a custom list by click on the site actions -> then
click on the “More Options”
Select the list from the categories and click on the “Custom
list” template and give the name to the list.
then choose the “Customize Form” option. By clicking on this icon the list will open in the Info path designer.
Then by creating you own rules in the infopath then you can publish the infopath then the list will customized and all the forms (New, Edit, and View) will open in the infopath.
How to customize the custom list in the infopath | SharePoint 2010