Flying spells are more movie magick than anything else, but when I see that people are searching for things like this, I feel obligated to help out. So here is my contribution to your search for flying spells.
As you should figure out on your own, true flying spells are not real. You can't a legitimate spell and literally start to soar through the air like a bird. Sorry.
This is a more metaphorical type of flying spell, to help give your spirit some wings. Consider it a way to bring new joy, inspiration and motivation into your life.
If you only have access to regular dried mugwort, you should use a mortar and pestle (or even a rolling pin) to crush it down into a real powder.
Set up some altar space and start burning the lavender incense. Let the smoke flow through your home, and drift around you. When the stick is finished, save the ashes. Mix the ashes with a few tablespoons of flour and some powdered mugwort. Store this somewhere safe until the next step of the spell.
On a breezy day, you need to take your materials and go outside. A small hill is best but any open field (or yard) would do. Lightly brush the feather into your spell dust and shake it above your head. As you watch the powder blow in the breeze, you'll feel your spirit take flight too.
Flight of Dreams
This is a bit of dream magick, to bring dreams and visions of flying, which can be an exhilarating experience.
Add one drop of both oils to the feather, and hold it in the air for a few moments to let the oil soak in a bit. The next night, sprinkle some chamomile under your pillow, and place the feather. You'll start to have dreams of flight within a night or two. If the feather is wet with oil, go ahead and use a towel or cloth to protect your pillow.
This is one classic bit of witchcraft that I couldn't leave out on the subject of flying spells. flying ointment is a very old type of herbal charm that has long been the source of occult legend. In truth, it more likely just helped witches to "astral travel" rather than actually fly.
True flying ointment has ingredients too toxic for me to safely share (things like henbane, hemlock, mandrake and belladonna). I haven't had too much luck finding good safe recipes for flying ointment but I will keep looking.