Dwarves are long lived, stout and hearty. Both genders can grow beards, and the way you wear your beards (or not) can be used to signal different things, depending on the family. Dwarves are deeply connected with the physical world and have a natural sense of equilibrium that essentially tells them how far underground they are. When on the surface, many dwarves feel some initial mild discomfort, and dwarf lore is full of tall tales of falling into the sky. In the Stellar sea, this is infinitely worse, and they suffer an discomfort akin to seasickness. Even those who adapt, find it unpleasant.
Dwarven magic is rooted in the connections to their family, both in life and in death. When a Dwarf pases on, there is a thread that connects their body to the afterlife. The greater the dwarf, the greater the thread. Dwarves have learned to harness this connection, and venerate the dead in great temples. THey build machines that run on these conenctions, both powering the great engines to simple machines. When dwarves loose access to their dead, it is the greatest Tragedy.
Dwarves are very Family oriented. Dwarves have no Cultural issue with marrying from within the family, though not your Immediate family, but if a Dwarf family is big enough, you marry a 2nd cousin or a 3rd Cousin. Dwarves don't suffer Imbreeding i don't think, but it is still concidered uncool to marry your sister. But it adds this interest tension of a Dwarf house that gets to small starts to look weird, and you get like Hill Dawrves, whos family trees are maybe not as wide as other dwarves would prefer. This all ties into Dwarf Magic, since it is Ancestor based, you need to be related to the dwarf to really use it as a battery to do shit with it. Thus Truly ancient Dwarf Burial sights are prized becuase they Do DO inter family Marriages to seal peace or whatever and its a big deal, cause it links the families ancestors!
Also Evil Dwarves, the Dureguer, are not "Evil" per say, they just culturall have broken from this tradition and intermarry. This is an affront to most dwarves and so they really hate each other.
You could elaborate blood adoption ceremonies and blood brother esque ceremonies that are all about tying someone, at least symbolically, to the family line. Blood brothers is the highest honor a non dwarf can be given because to share blood is to share ancestors.