What is the recommended method of styling an iOS app? For example, if there are multiple labels or text views how can updating font style/color at one place update the style
You can use a third-party abstraction of UIAppearance:
Using a Storyboard has a lot of benefits, but many style options aren't available, not the least of which is custom fonts. If you want a deeply-customized UI, you will need some style code to make it happen.