jacks can help ... although I use them sometimes, there is really no need for them. Boro has a relatively short work span, so you're better off using a graphite rod, if anything. Jacks chill the glass really quickly and if you're not careful, can leave scratches as well, which graphite won't.
Sorry about the freaky perspective on the photo, my camera seems to pull the image at the edges on zoom and it makes the feet look weird ... they're not. These are all goblets for my mum's collection, she requested a bunch of different goblets for celebrations. The only tooling i used on these is the paddle on the foot to make sure it's straight and a marver for a couple of the stems (and of course grabbers to hold all the bits
). The sandblasted one is about 15 years old.
You have to remember that using tools leaves tool marks ... it's a personal preference, but I don't like tool marks on my goblet cups and feet.
The trick is to set up the shape first, blow the top really thin, remove the point to a reasonably small hole and open it in the flame by turning carefully. It pays to know your flame and the heat in your glass really well.
But yeh, a long graphite rod, preferably set into a handle, will do the trick just as well as a pair of jacks and not suck the heat out of the glass at a fast rate of knots. If you want to get really fancy, you could make yourself a pair of graphite bladed pachioffis, those are basically jacks with round dowel shaped blades, usually cherry wood soaked in water, but for lampworking graphite is more practicable. They're also cheaper than jacks.
I'm lucky I did some years at the furnace, so I have all these things to play with, although I generally opt to work without them. Part of my glass working philosophy is to use as few tools as possible in my work, if any at all.