Make two short cylinders from similar portions of clay: keep one and cut the other vertically. The intact pot shows the silhouette; the cut section shows where the clay went. This exercise works best with a plain, open form before handles or decoration are added.
Set a reachable height
Sketch a short upright profile with an opening wide enough to reach inside comfortably. Use it to notice when the wall starts drifting outward. Exact dimensions matter less here than keeping the intended direction of the wall.
Prepare similar portions for the two pieces. Keep their target height and opening close enough that their profiles can be compared afterward.
Build the floor and wall
Open a floor suited to the cylinder and check its remaining thickness. The inside corner should not become a deep trench. A weak ring there can undermine a wall even when its upper portion looks substantial.
Begin pulls in the lower wall, where clay is still available to move upward. Keep the opening contained while establishing height. You can practice widening into a bowl after you can maintain the simpler upright profile.
Watch for outward drift
Step back visually after each meaningful pull. A cone that widens upward may reflect outward hand movement, speed or softening clay. A pinched middle suggests uneven pressure. A leaning rim may have been disturbed by the release of a hand rather than by the whole cylinder being off center.
If the opening spreads, ease off and check the lower support before trying to squeeze the rim inward. Repeated collaring of a thin upper wall can leave a heavy roll perched above a weak section.
Keep one and cut one
Keep a reasonably stable example for later trimming or comparison. Finish its rim gently, remove interior water and release it without squeezing the sides. The retained piece lets you see how a wet cylinder changes as it firms.
Stop the wheel and cut the second cylinder vertically. Compare the floor, the lower wall, the middle and the rim. A thick lower band shows where clay stayed behind; an abrupt thin ring identifies a point of excessive pressure. Lay the section beside your sketch and choose which area the next attempt needs to change.
Questions about this topic
Should I add a handle to the first cylinder?
You can save a suitable one for a separate handle lesson. Do not let that expectation stop you from cutting a practice piece apart to inspect it.
Is a slightly tapered cylinder a failure?
No. It can be useful evidence or a deliberate form. The question is whether the taper was controlled and whether the walls support the intended use.