Making a few different shapes and colors, but in general they look the same and have the same steps. A few common things I use in this tutorial:
- Expand/Inset - This is a shortcut to make an outline. Like in the 4th step, I copy the 3rd step, expand that a few pixels, paste in place what I copied and inset that a few pixels.
- Gradients - I like to use this in subtle ways because you can get overboard and make things look tacky.
Don't worry about color a lot to start with, can do it all in grey if you want. Contrast is more important because you want either the liquid to stand out or the glass part. If it all blends in, you'll just have an empty looking potion container.