Throwing repeats of the same shape and size has been one recent challenge. I have a certain mug shape in mind that's good for keeping tea warm... these ones fresh from the wheel (below) are the products of yesterday's brief throwing session. I haven't tried using any guides or measurements for repeats as yet - I just start with the same amount of clay and try to repeat it by sight. Might try some measurement guides next time to compare.
Another wheel challenge for this week has been attempting lids for the first time.
I've only tried one type so far but was quite excited by this exercise and now want to try other types - especially ones that require a 'gallery' on the pot rim. These ones that I've done don't meld so well with the pot shape - they look a bit like they're little mushroom tops sitting on top. Fun though, and I think they'll make nice little tea caddies or garlic storage jars.
Very happy with my new 'wiry buttons' slip stencil/ sgrafitto design on them too.
Here's a picture of some real wiry buttons (image is by Chris Clarke - I got it here on the web).