I have been using Procreate for sometime now, but that didn't mean I either knew or remembered a number of tips shared in this class.  The most useful for me was the tip to create an outline (sticker effect).  However, I save a step in the beginning after I duplicate my layer that I want the outline for, I select the Hue/Saturation/Brightness option under adjustments and slide the brightness slider to 100.  Then I follow the rest of Claire's instructions to create the outline.  

I have never thought to try applying a gradient adjustment to change colors.  I'm totally going to remember this one. 

Here is my sticker that I created from a very recent class (on the left) and then with a gradient adjustment applied (on the right).  

Thanks Claire!