It all depends on the size of your plants and your preference. Small herbs and microgreens can do quite well in foam collars, which provide support by enclosing the stem, while heavy specimens like potatoes are likely to be too heavy once the spuds start to grow. In those cases, aeroponics farmers may opt for net cups, which hold the weight of the root mass while allowing the roots to grow between the plastic net structure.
If you find that a net cup is insufficient to provide the support you need, some sort of media can be added to the cup to give the roots more to grab on, but choose your media carefully since it will need to be either disposed of at the end of the grow cycle or thoroughly disinfected. smooth material like plastic balls or marbles have fewer nooks and crannies for germs and spores to hide in.
