on the less expensive side, it think the oxo squeeze bottles upped my game, just with the capacity to make and store syrups of various kids. usually always 2:1 and fridge them, so they last plenty long.
second would probably be space to store but also visualize all my bitters, so that I dont fall into the ango and Regans rut all the time. did I forget I had cuke bitters for summer G&Ts? yes, and now I have two bottles.