In a jar, add 130 grams of the gluten-free flour and 130 grams of room temperature water. Mix until well combined and cover the jar with cheesecloth (or a paper towel and rubber band works fine too!) Store at room temperature for one day.
The next day, scoop out about half of your starter (it should've grown a bit overnight!) and discard this. You can always save your sourdough discard to use in other recipes if you'd like, or just dispose of it.
Add another 130 grams flour and 130 grams water to the remaining starter and mix well. Cover and return to counter for another day.
The next day, discard half and repeat the previous step.
Repeat this for 7-10 days and you should have an active starter that is ready to be baked! After this point, you can store your starter in the fridge and only feed it every few days.