Trouble Trimming, Beginner's Bump, and Double Dipping

Make sure when you trim a foot that only the unglazed circumference of it makes contact with the kiln shelf during the firing process.  Otherwise, centre of the underbelly will turn out like this because the glaze will stick and fuse to the shelf and leave you with an unsightly nubbin on the bottom of your dinnerware.

It's not terribly noticeable in this picture, but there's a a slight "beginners' bump" in the bottom of this bowl.  "Beginners' bump" is a slight irregularity in the bottom of the inner contour of a bowl.  It is a tell tale sign of a new potter.  The only way around it is through practice, patience, and attention to detail.  You can also use a variety of tools to ensure a consistent concave curvature in wheel thrown bowls.  Another thing that comes out in this image is how speckled the yellow glaze is.  These brown specks and delicate cracks came out due to a second firing.  They're quite nice and give it a beautiful textured look.

This bowl was glazed with an Autumn Yellow dipping glaze.  Peacock Green was used to glaze the foot.  The dipping glaze was too viscous and I'm also guilty of over dipping which resulted in a thick, creeping, cottage cheesy look.