Reddit reviews Polaroid Hot Shoe Three Axis Triple Bubble Spirit Level for Canon and Nikon Digital and Film Cameras

Most cameras have a built in virtual-horizon you can use to at least get level. Or better yet, get one of these hot-shoe mounted bubble-levels and you can really square things up.

Use live-view on your camera if you can. it will help you visualize the final product.

Just try to keep the vertical lines vertical by having the sensor exactly parallel with them. If the sensor is not parallel with the vertical elements then they will appear to lean towards or away from the viewer. In other words if the camera is pointed up or down even slightly, then the upright elements will lean forwards or backwards.

This type of alignment is easier on large format film cameras with lots of movements. Or you can buy an incredibly expensive PC (perspective correcting) lens so you can adjust the perspective in-camera quite easily.

Lighting looks great!

The one thing that I can't tell is if the photo was taken slightly askew. It seems like the right side of the bowl is more in focus than the left, which would explain why the grains and such on the left hand side seem to be tilted. I purchased a 3-axis bubble level like this one and it has made straightening my planes so much easier than eyeballing it.

edit: fixed a sentence