I would immediately mix up more of the same mixes so that they're steeping while you're vaping this batch. You might not have enough bottles and that's a tricky one. You can either buy more now and then you end up with too many, or you can allow your bottle collection to grow over time as you convert old nic and concentrate and commercial juice bottles into mixing/testing bottles.
I have lots of bottles now, so many that if I had to mix in every one, I'd have about two years supply of juice. I once bought 30x10ml dropper bottles for testing, which was a waste because I have soooooo many old 10ml concentrate bottles now from using up flavours. Give them a looooong soak in salty hot water to remove residual aroma and they're fine for single-flavour testing. Also, even though I don't buy commercial juice, I somehow get a lot of it. Competitions, giveaways, vape meets, people sending me juice to test, etc. So, if you're patient, you can DIY without ever needing to buy bottles. Inevitably as a DIYer, you end up with tons of them.
Thanks for the tip on the salt mix!