This is my almost done tube of facial foam.
Step 1 : puff the tube up so there is space for air inside. Step 2 : add water (the amount depends on how much you have left in the tube, trial and error is the only way. Always start very little)
Step 3 : close the lid and shake very well.
Pour out the soap, it should become a foamy fluid like this. You can now use this to clean your face!