Well....
You don't want to celebrate something if you have no feeling for why you are doing it. I am agriculturally and physical-world oriented so I am focused on two things: the longest day of the year and the celebration of light, the respite between planting and harvest. I'll have a fire, do a working for my plants, infuse a song with magic, dance for joy.
The Wiccan group I studied with would have a bonfire on the beach and empower protective amulets in the shape of fire wheels for the year during the Midsummer ritual - they would celebrate Litha at the Solstice.
Midsummer is the time for weddings. Whereas people would indulge in casual passions at Beltaine they might acknowledge deep, abiding love at Midsummer and enter commitments.
I found a solitary ritual, Wiccan in flavor, I think, over at the Wiccan-Pagan Times website:
http://www.twpt.com/ritualboudica1.htm