On long hikes, I have a tendency to lose things. So I've found ways to attach everything to my pack or to my clothing. I'll try to post a few solutions, starting with this one.
I've got a cheap basic case for my iPhone. On top of that case, I have my own no-bling system. Using tubes for 1.5" bicycle tires, I cut rings of about 3/4". Wrap those around the top and bottom of my iPhone. Then, use the tubes to anchor an attachment string with a clip at the end. I've used this now during ~15 weeks of hiking, and all around town too. This does a few things for me...
1. The tubes cover the part of the glass screen which is not part of the active display, giving a little protection in case I drop it.
2. The top tube covers the camera lens. Advantage is that the lens is protected. Disadvantage is that I have to remove the tube each time I take a picture; this isn't a big deal.
3. The tubes wrap around the rounded corners of the phone, which is the place that takes a direct hit if I drop the phone, so there's a bit more protection from damage during a fall.
4. Most important - the tubes are a very snug fit, so they really anchor the string. The phone is always clipped to a belt-loop or a loop of cord that I've sewn into the top of my pants pocket. a) I don't lose the dang phone, and b) if I drop it then it only falls as far as my knees. Key here is to use tubes for 1.5" tire - fatter tubes would be a sloppy fit, and thinner tubes wouldn't be large enough.
Maybe I'll bring a tube to GGG #5 at Coe in January and people can cut pieces from it :)