Instructions depend on how simple or how elaborate you want to get.
My daughter's waist-length veil was basically a large clear comb with the veil (tulle) layers sewed to it. It also had small crystals and tiny silk flowers sewed on here and there. Only the blusher (the layer that the bride wears over her face while walking up the aisle) was trimmed in the same fabric as her dress.
You can also attach the veil to a wreath of flowers to add another level of design to it.
OR you can wear a tiara or wreath separate from the veil. When the veil is removed the tiara or wreath can remain.