Here's the perfect 10ml bottle for me, someone who cleans and reuses:-
Made of PET (the hard plastic) for durability but with a soft section in the wall for squeezing ... FlavourArt use these, it's the ideal compromise.
Short, fat tip, easy to remove.
A small scale on the side, running 1ml to 11ml in 1ml increments, raised part of the plastic moulding, so I know exactly how much is in each bottle.
A steeper shoulder near the top so the last ml of juice doesn't stay in the bottle.
Too late for me now, as I have over 140 x 10ml bottles and 20 x 5ml bottles, plus a handful of 100ml bottles.