So earlier today I was leveling some ground and getting a lot of soil from it. So I decided to turn it into Prisms. Simple enough, right? So I took an inventory full of soil (minus two slots for the firebrand and two slots for my keyring and flask) and loaded a coal into my crucible. Then I performed the following steps:
1. Move to my branches stockpile, take two branches, and move back to my crucible.
2. Drink from my flask to have enough stamina.
3. Craft a firebrand (takes some time), then light the crucible. The firebrand burns out during the lighting process.
4. Move to my branches stockpile, take two branches, and move back to my crucible.
5. Drink from my flask to have enough stamina.
6. Craft a firebrand (takes some time), then light the crucible. The firebrand burns out during the lighting process.
7. Move to my branches stockpile. Notice there's only one branch left.
8. Take a block from my block stockpile to split it into branches. Drop three Soil onto the ground to have enough space for the branches. Click 'split' only to get the message that I need an axe for that.
9. Head to my equipment cupboard to switch my shovel with my stone axe.
10. Split the block and store the three other branches in my branches stockpile.
11. Quickly grab the three dropped soil before it messes up the elevation.
12. Move back to my crucible.
13. Craft a firebrand (takes some time). Right when it's about to complete, 'you are too tired to craft'.
14. Drink from my flask to have enough stamina.
15. Craft a firebrand (takes some time), then light the crucible. Finally, the crucible is lit and I can start producing glass.
During glass production, I had to refill my flask because it was all empty after the herculean task that is lighting a crucible.