Measure your mobile phone against the bottle, to be sure the bottle isn’t too big or too small. Wash the bottle and let it dry. Hold your phone up to the bottle, starting at the bottom and decide how high you want the front of the holder to be. Then make a line with a marker across the front at that point (do not use a permanent marker).
Turn the bottle around and continue the line to the back while curving the back upwards.
Cut the bottle with scissors or a box cutter.
Draw rectangle on the upper back of the bottle large enough to fit your charger.
Sand paper all edges to smooth out and clean the marker off with nail polish. Wrap a piece of ribbon around the bottle, cut to size then glue in place.