bottle sling knot for clipping any water bottle to harness

experts say not to clip the plastic lid keeper of a nalgene water bottle as it will eventually break making a missile as tested by howNOT2

tie a bottle sling knot using a shoe lace or para cord or thin cordelette or a dynema sling 

or use tape and make a loop as a handle stuck to the sides and going 2-3 inches above the lid and fold the tape in half onto itself and then secure the loop with one more pass of tape around the bottle

easier to follow "jug sling" link

PPP has an easily transferable knot on pg 326 of Hooking Up. 

I've always taped the crap out of a piece of webbing to the sides of my bottles. Then just clip it to the harness. Works flawlessly and in the case of an emergency, you've got extra tape and some webbing to use. The bottle sling knot or any other purely tied-on knot approach is liable to loosen and create those missiles you're worried about.

This might be my favorite knot-instruction image ever.

Clove hitch a loop of cord underneath lip of bottle, it's that easy. 

Edit, stuck at desk:

Some doubt this as a reliable solution, even partners who trust me with their lives haven't trusted me on this issue at first. But in time? they've seen that damnit it works. Fifteen years in the valley and greater Sierra, climbing the wide and physical stuff I like, and it does not fail. 

My exciting personal moment related to this: 

Hayden Kennedy and Will Stanhope passed us on a Freerider day as we were toiling up the Salathe, somewhere after the Ear. 

Stanhope, sharing the belay w us as Kennedy fired the pitch above, asked if we could spare a sip of water. I passed him a 1L bottle with my simple little clove hitch loop and told him to keep it for the send. 

"Thanks! ... but... is that going to hold?" Eyeing my loop w doubt (but in a polite, Canadian way). "It'll hold, William!"

About 3 hours later they came rapping past us, Kennedy's finger with a nasty flapper from the Boulder problem. Water bottle? Empty and still clipped to Stanhope's harness. 

Doesn't fail!

Postscript: He left the bottle w me, and I still use it to this day, and it helps me to send.

Double postscript: Same partner and I bumped into Stanhope at the Cookie a couple weekends ago. Was sorely tempted to bring up that day on the Salathe, and the clove-on-bottle method to find out if he's adopted it

I usually go with one or two 500ml nalgenes, clipped to the lid. Honestly haven't tested them, and don't think I've ever even fallen with them attached. They're a nice size for distributing weight, though!

Constrictor hitch seems like a legit way to carry most anything.

I just duct tape a piece of cord onto a nalgene. Bonus is that you have duct tape for emergencies, which has come in handy many times. 

barrel hitch