There are many Seders written just for Tu B’Shevat. You can find several here http://urj.org/holidays/tubishvat/101/index.cfm#seder
I am especially drawn to the one entitled Adults’ Seder from Temple Shalom in Aberdeen, NJ. You can choose to create a complete evening event or just add a few simple touches to your dinner.
On the first page, there’s a lovely explanation of how the mystical sages of Safed in the 16th century thought about “God as a tree of life, whose roots were in the heavens, and whose branches extended toward earth, bringing all of us life and blessing.”
There are also descriptions of Tu B’Shevat traditions from around the globe, like the one in Persia where people climb on the roof, lower an empty basket through their chimney, then fill it with fruit before raising it again.
Want to learn about the symbolism of the levels of creation, represented by the different types of fruits and nuts? It’s all here.
You might also have heard about drinking four cups of wine, as we do on Passover. In a Tu B’Shevat seder, however, we don’t pour all four cups from the same bottle of wine. Instead, it’s typical for these four cups to vary from white “representing the winter season at its peak” to white tinged with red, symbolizing “the beginnings of the springtime and the earth’s reawakening” to reddish to full red.
Want to focus on the eating of different categories of fruit, rather than on drinking wine? That’s explained here, as well, along with blessings, songs, poems, excerpts from Psalms and more.
Kudos to the creators of this Seder!