You can design custom layouts then hide them until you want to use them on iOS 14. Add the desired icons and widgets to a home screen page, maybe just for work or a specific activity, then you'll be ready to hide it until needed.
Long press anywhere on the home screen
When in "jiggle mode" dots representing your home screen will appear at the bottom of the screen
Tap on these dots to see an overview of all of your home screens
Tap the checks to choose if a home screen is displayed or not
Swipe up or tap "Done" to finish editing pages