Let’s talk about the “One who Presides”.
Forseti is an intriguing god in that he directly opposes the common perception of the brutal, war-king image of the Viking Age. Because the Viking Age is defined by two seemingly contradicting sides. Outside of the longhouse- the courtrooms and parliaments and senates of the time-the world was a rather compassionless landscape. It was a tribal place, where strength and power were mostly exercised in tangible ways. The strong took from the weak, and strength dictated power.
Yet, inside the longhouse, poetry and skalds and frith reigned free. Lawspeakers kept the law, and the law was often comprehensive, convoluted, and filled with nuance. Forseti then is an important figure, embodying the diplomatic stance that very much existed at the time, even if it was overshadowed in many ways by the more dramatic outside world that has since been popularised and romanticised.
Saying that, we also have very little on Forseti himself, bar that he is the son of Baldr and Nanna, has “the best of courts”, and resides in Glitnir (“the one who shines”). It seems that he takes very much after his father, who was the gleaming, beautiful god of the Aesir, and embodies the Aesir predilection towards civility once peace has been achieved.
While Forseti is often strongly associated with justice and reconciliation, those associations really have only been gleaned from the above attestations, though he stands as a direct opposite to Týr, who Snorri notably refers to as “not called the reconciler of men” in Gylfaginning. After all, Tyr’s realm is more tied to war and battle – specifically the formalities of it - the honour, the sacrifice, the treaties and so on, rather than the almost legal realm of Forseti. Or, to put it another way, Forseti is often seen as a talker to Tyr’s do-er.
With all of that in mind, modern heathens tend to associate Forseti with the thing, presiding over the assembly to ensure peaceful and productive discourse. Like Víðarr, Forseti is often seen as a sort of silent observer type, and those that worship Forseti often call upon him to aid in meditative states to calm the body and mind, and to attain a sense of clarity and focus.