Strength - Dwarves are much stronger than beings that are even larger than they are. Their strength can be referenced in battle as fierceness, in injury and as having an unnaturally high endurance and quick healing, or in sexual activities.
Gold and Jewels - Dwarves are enamored of any beautiful metal or rock. They also mine baser metals, but they're generally associated with wealth.
Crafting - Dwarves in Tolkien's works are generally the best metalworkers and stonemasons in Middle Earth. Dwarves can focus almost entirely on the craftsmanship of jewelry or weapon that are then heirlooms handed down in generations or they may be crafted by a particular dwarf. The giving of well-crafted gifts to someone else is almost always the focus of such works, and they frequently involve romance and courtship.
Khuzdul and Iglishmêk - Tolkien invented two languages for dwarves: Khuzdul, which is spoken and written, and Iglishmêk, which is a sign language. Online dictionaries of Tolkien's invented language have sprung up, and the use of Khuzdul in works, with a gloss in the notes at the end of each chapter, has become quite common. Iglishmêk is also commonly used, but it is rarely described. In fanworks, Bifur is the dwarf most likely to use this language, due to his injury.
Dwarven Women (dwarrowdams or dams) - It is said that there are few dwarf-women, probably no more than a third of their entire population. They seldom walk abroad except at great need. They are in voice and appearance, and in garb if they must go on a journey, so like to the dwarf-men that the eyes and ears of other peoples cannot tell them apart." Fandom has taken this to mean that male/male romances are often depicted as common. This also sometimes feeds a trope where only dams are allowed to initiate sexual contact, however in my stories this last part will not be true ;)
Daughters - As a result of the rarity of Dwarven women, many fanworks depict the birth of a daughter as particularly noteworthy and a great cause for celebration.
Courtship Rituals - Following the traditional romcom style of awkward relationship development, dwarves are often depicted as having complicated courtship rituals that even they often struggle to follow. Anyone not a dwarf tends to bumble badly or have no idea what's going on. Hand-crafted gifts are a common theme.
Ones - Similar to the soulmate trope, dwarves (and other beings of Middle Earth) are sometimes depicted as having a One, someone who is basically their one true love and half their soul. How Ones find each other, whether they're both aware of the situation, and how many times they fumble the situation varies from work to work.
Hammer and Anvil - Instead of Top and Bottom, some dwarf works use "Hammer" and "Anvil" instead.
Hair Braiding - Based on the complex hairpieces of the dwarves in the movies, this is a very common culture trope in the fandom, nearly universal in Dwarf/Non-dwarf works. Braiding is usually explained as something only done between immediate family members or during courtship, with the usual cultural mishaps being common in works. Courtship beads are often involved; these are intricately designed beads that act as clasps to hold the end of a braid in place. There are several artworks focused on braiding or hair washing/brushing. Non-braiding hair-related cultural elements have also been invented, such as personal combs. In the books, removing beards was a sign of shame.
A Dwarf believes that a piece of them is always missing until they’ve met their One. It’s a feeling no one can describe. Its like a soul mate of sorts and Dwarves can sense when they have finally met their One. When a Dwarf finds their One it does not mean immediate attraction or even likeness. It may take days, weeks, months or even a few years to realise their attraction and even then they might not find their One. However once a Dwarf recognises their One they can feel their emotions wether they feel love, fear hate etc. Once in close proximity a Dwarf and their once can share thoughts and sense what the other is thinking. A Dwarf can grow close to another, but the connection will never be as close as a Dwarf is with their One. For example a Dwarf can grow so close to another they consider the other family, such as brothers and sisters, but their true love will only remain for their One. When it comes to love Dwarves have no bias however once a Dwarf’s One dies, wether they know it or not, they will never marry again/ or at all.