Stir together the food coloring (if using) and the contact solution.
In a mixing bowl, add the glue.
Stir in the baking soda with the glue.
Then, stir in the colored contact solution.
Once the slime is mostly mixed together, add the shaving cream and fold in.
Knead with your hands to really mix well (the slime will become less sticky). This can take a few minutes to reached the desired consistency.
Notes
Fluffy slime is not safe to eat.I use separate mixing bowls and spoons for crafting/activities like slime. If you're going to make lots of slime I recommend it!Store slime in an airtight container when not in use.If you're planning on making lots of slime, I'd recommend buying your glue in bulk.Make sure you're using shaving cream and not a gel.The contact solution that you're using must have boric acid and sodium borate; otherwise, it will not form the slimy consistency (I've linked what I use in the post).If you decide to make multiple colors, keep in mind that after they've been combined for a bit they may turn a bit grey or muddy looking—similar to play dough colors being combined.