I cut a whole in my canopy installed a recessed lip for them to rest on. I don't recommend that. Too much work. I eventually grabbed a an aquatic life Hybrid T5 Fixture and mounted them in that. I love my radions they throw shadow like all LED's Adding the T5's helped.
I have seen them zip tied too. As long as they are secure it doesn't matter. Thats the beauty of a canopy!