De or het haarstyling?

The correct Dutch article is:

de haarstyling

Rule Words ending in -ing: almost always de. See the rule

How to use haarstyling

the haarstylingde haarstyling
this haarstylingdeze haarstyling
that haarstylingdie haarstyling
our haarstylingonze haarstyling
your haarstylingjouw haarstyling
every haarstylingelke haarstyling
which haarstyling?welke haarstyling?
a big haarstyling / the big haarstylingeen grote haarstyling, de grote haarstyling