I use cable ties. You can buy them in bulk at hardware stores. They can be clear, black or bright colors and they come in many lengths. Once you set them they stay the diameter you set. They have to be cut to be removed. I've used many; I like these best. I put them on pretty loosely. Happy tying!

I use velcro. I've seen this stuff in brown or black but I can't remeber where.

http://www.leevalley.com/garden/page.aspx?c=2&p=45293&cat=2,43319,33283&ap=1

I use the plain old brown twine (jute?), find it blends in and is almost invisible.

A......

I hate the neon green stuff so now I use cut up nylons.