Use local.xml in theme layout for Updating Handles

Use local xml in layout file to update the handles

Step 1

Create local.xml in your custom theme as app/design/frontend/[package]/[theme]/layout/

Step 2

Create the layout code in local.xml and update the layout handles that you want in custom theme.

Within the layout tag, update the base xml handles. For example, want to remove the newsletter globally in left column for your current theme.