well… can’t really give you a straight answer on this… unfortunately plastic bottles haven’t worked well for me…
when i started making my own mixes etc ofcourse i started using plastic bottles as most of us (i think) …
the thing is that in most of my mixes i use some really strong flavors such as cinnamon is… (cinnamon TPA or Cinnamon Red Hots) the thing is that even after many tries to clean up the smells wasn’t really successful
warm baths…
trying to clean them with hot water
or any other way i tried sometimes the smell couldn’t go away, in some other cases even if i couldn’t get any smell from the bottles there were times i noticed notes of previous mixes in the mix i made later…
imho the best way is using dark glass bottles
Dark color just for precausion less light gets inside so nic does get changes because of light or whatever… (PG and VG are also light sensitive… though sun never gets in my closet 
)
Glass : well… imho eliquids steep better in there while glass at the same time gets cleaned up easier and you can use the bottle as many times you wish…
i am buying from times to times small plastic bottles of like 30-50ml to test new recipes or mixes… but i am using them just for 1 time… if the recipe goes well, i start making them in larger glass bottles (200-300 or even up to 1liter bottles) else i am throwing them away or using them for refilling my tanks with the same recipe for some time… another thing that i take in mind is the cost… buying small plastic bottles (30-50ml) (usually buying them from vaping shops) cost like 1 - 1,5euros) while i can get a 500ml bottle with like 2euros… it’s not much expensive while at the same time in terms of deeper time they come much cheaper since i can use them again and again without any problems…
hope i helped ya 
gl and hf