On a rod
Take one rod, paint stripes of other colours on it, melt it all in, then either attach another rod to the end to let you pull and twist, or use a pair of pliers or hefty tweezers. You want to pull out and twist at the same time – either rotate both hands in opposite directions, or just spin one rod and pull with the other. (The second way is easier if using pliers!)
Pull slowly until you see what kind of diameter that gives you, as going too fast makes a very thin twistie. You don’t need to make a massively long twistie and it doesn’t need to be uniform: about 5 inches long is a useful length. It spreads out when melted in and differences in diameter can be a good look. If the twist isn’t as tight as you like, you can twist it more as you apply it.
This first way will make a smallish twistie because your base is a single rod thickness. To have a larger starting base you can fold the rod back on itself, or melt and form it into a plug shape before adding lines.
The downside to making twisties on the rod is that you can thermal shock the rod just past the section you are using for your twistie. This isn’t much fun. You can also heat a bit too far along the rod and end up with your mass on a bendy stick that you’re losing control of.
The alternative is to make your twistie on a metal base – use a mandrel or stainless steel chopstick. (For a mandrel, a thicker one is better – 2.4 or 3mm is fine, but 1.6mm is a little wimpy and prone to bending). Heat the end of the mandrel so it is only just glowing red, and your glass will stick to it. You now have a more stable base to build up your twistie on. At the end, you can heat up the bit of glass left on the metal and stick it into your water pot – it’ll shock off with a hissing and popping noise. It’s better to have a dedicated mandrel for making twisties, so you don’t end up putting bead release over one that might still have a little glass on the end and cause your beads to stick.
In a lollypop shape
You can do this on either the rod or on steel. Start by making a ball, then flatten it into a lollypop shape. You can then add your other stripes of colours to this. It changes the proportions of where the colours show up once you have heated it back up and twisted it all. Because you have more surface area, your colour sections can be bigger, or a combination of large areas and fine lines.
Colour picks: choosing a random assortment of opaques is an easy place to start, or go for transparents over white – do be careful about strongly reacting colours though – generally speaking it is wise to avoid ivory unless you know the combo is one you want!
As well as just adding stripes of colours, you can obviously encase the whole thing in transparents too.
Effetre black will be obviously purple in a lot of twisties while CiM tuxedo is usually grey-blue. CiM Hades will web and react when the twistie is superheated onto the bead – this can be a good effect. Reichenbach deep black is best for a dense unreactive black that can make very fine lines.
Striking silver glass makes for good twisties as the small amount of glass is easy to get very hot as you are melting it in. Reichenbach multicolour, dark multicolour, magic or raku with stripes of deep black come out great. (You might still get browns and tans with raku, but they are good-looking browns and tans!)
Reducing silver glasses also give great effects. The base colour they are paired with can make quite a difference. CiM greys are generally good for this, as well as reactive colours like canyon de chelly, stoneground, opal yellow.
If you pull and *don’t* twist, you will get straight striped cane which is handy for vines or flower petals.