Provider Hosted Apps on SharePoint 2013 are awesome. If you don't want to go with an Azure Access Control Service (ACS) subscription in an Office365 tenant, you can use High Trust or Sever-to-Server Apps. There's lots of good documentation about this on the internet already, so I will not go into details on these. If you have set up your SharePoint 2013 Development environment for these Apps and want to explore the good world of Provider Hosted High Trust Apps, you need to set up a trust between most likely your IIS where you will host your Apps and your SharePoint 2013 farm. The below script will do exactly that for you by simply executing the PowerShell.
Download the script
You can just run the script and accept the default values or you can override them and provide your own input. The following arguments are supported:
Once it is done running, it will also create a file IssuerID.txt on your desktop where you can find the IssuerID under which the trust was established.
You can also use Get-Help .\CreateTrustForHighTrustApps.ps1 to get help with the usage of this script.