Samhain is traditionally a time to honor our ancestors–both blood and spirit–and of our dead in general. This is done in a number of ways depending on the person, their own personal connections with the dead and with chthonic deities, and whatever tradition or traditions they come from.
It’s a good time of year to visit cemeteries, especially those who have graves of anyone who is deceased with whom you have a personal connection. Our ancestors can be of blood, but also of spirit: ancestors based on similarity of tradition, shared interests, or chosen pursuits are just as valid. Leaving flowers on graves is traditional practice even in mainstream culture. If you don’t have a cemetery to go to and/or know anyone in particular whose grave site you could visit, there are often shrines dedicated to the dead for events in history such as the Salem Witch Trials, 9/11, war memorials, things of that nature. Those too would be perfectly acceptable places to pay respects in order to honor the dead on Samhain.
In my own trad, we keep pictures of the dead who were important to our tradition and practices on an ancestral shrine. My own ancestral shrine has items and pictures from some of my dead relatives but also pictures of friends of mine who passed away. If you don’t have anyone who was close to you and/or don’t feel particularly connected with your ancestors, the famous dead are perfectly fine too. Having someone who inspired and inspires you is valid. Have Carrie Fisher on your shrine if you want. According to my Ancestry app, she’s apparently my ninth cousin or something or other, so it’s not totally off the wall!
Along with pictures and items on my ancestral shrine, I also keep a tealight candle there. Lighting candles on shrines is a good way of honoring the deceased. Personal practices in general around the dead and your ancestors can include similar ideas and can be expanded to include things such as cakes, bread, or wine. If someone whom you knew passed away and liked a particular food or beverage, either having it that day or leaving it out for them is a perfectly acceptable way to honor them.
Eating food or drinking beverages that your deceased friends and/or family enjoyed in life can also be a part of a dumb supper. Pagan dumb suppers are feasts held in honor of the dead, and can be done alone or in a group of other people–but with a group is best so it can truly be experienced in silence. A place is set out for the honored dead at the table, and everyone dines together. One suggested practice is that everyone writes down the names of the dead whom they wish to honor, and leaves them on the seat set aside for the dead. Such dumb suppers can be performed with or after other rituals, including a regular devotional/invocation to related deities, including Persephone, Hades, Hermes, and Hekate.
Honoring the dead on Samhain can be as simple or as elaborate as you like, depending on your situation and preferences. It has been my experience in keeping an ancestral shrine that it is the one shrine guaranteed to grow and expand as the years go on. Such is the nature of life, and of death.