So...what is easiest/quickest to use to measure 5-6 ml. and 89 ml. quantities...beakers, graduated cylinders, syringes ???
I'd say syringes would be the fastest, no muss way to measure small quantities. Downside (from when I used them years ago to fill carts) is the measurement marks are ink and will eventually rub off.
With my one and only batch, I used a combination of the supplies you mentioned for a 30ml batch. I admittedly splurged a little on the equipment. I could have gotten the job done with the larger cylinder, a 10ml syringe, and the appropriately sized empty bottle.
A 5ml disposable pipette worked fine for the tiny quantity of flavor. The narrow part is graduated in .25ml to 1ml near the bottom of the bulb. So presumably the bulb holds an additional 4ml if you filled it completely. Good enough to measure off 0.6 and 2.4ml of flavor. For a larger batch I'll use my 10ml cylinder.
I used 10 and 50 ml graduated cylinders for the larger quantities (4.2, 7.8, and 15ml). The only tip I can offer is pour slow. The cylinders fill fast and you'll miss your mark rather easy. When I did over fill a little, I reused the pipette to draw back down to the desired level and return the excess to the big bottle. I'll get better at this with practice.
I blended into a 50ml beaker both to see the measure and a large opening to stir it. I could have just blended into the empty 30ml bottle since that's how much I was making, then just shake it.
Get a tiny funnel. Filling those little bottles would have been a mess without it.
The cylinders are a little more pricey, but have more precise markings (0.2ml for the 50, 1ml for the 150). The beakers were marked, but in coarse increments (5ml for the 50, 12.5ml for the 150).
I chose those sizes since I planned to mix 30ml batches at first to get my flavors right, then move to 120ml bottles. I've previously bought my ready made liquids in 120ml bottles, which usually last me about 3-4 weeks. I figured that would be a good starting point until I decide on how frequently I feel like breaking out the lab equipment to make more, then clean and put it back away.