Still life objects don't have to be white to do value studies, although white objects certainly make it easier to ignore local color. If you are bored with your dishes, get some casts of classical sculptures to practice on. Or, a can of flat white spray paint and a box of old junk will work wonders for you. I often like to spray paint cheap plastic toys like dolls and animal figures for practice.
As far as setting up your still life, start with single objects before you worry about multiples. Use a single directional light and set your white object against a dark background for maximum contrast. When you do start working with multiple objects, try to create an interesting composition by using overlap and by placing some objects nearer and farther to create depth in your design.
As the ego shrinks, so the spirit expands.
One exercise we did was set up a massive still life using loads of objects with different textures and colours on different levels, it was a mountain of bric-a-brac. Over the course of a week we had to move around and pick out different interesting compositions, if you got bored with one bit you could just move to another bit.
If it's easy stuff you're starting with then maybe mix it up by putting your object against a white, then black, then grey background as you'll notice the values look alot different.
Do some research. Still life affords the artist a great deal of opportunity in design/composition, statement/idea and technical skill/craft. In fact, I think it is the one subject type that best captures all three of those elements. Use your imagination.
I found some time for a little still life value study yesterday.
It's incredibly difficult to get the correct values.
At first I thought the white on the light side was white, but then I noticed the tiniest of highlights and I'm like
The table I set it on was black or really really dark brownish and the background was greyish, getting all the values right was... unsuccessful.
But thanks for the great tips though guys, I love the spray painting stuff idea. I would love to buy some casts, but they are hella expensive.
It's also very useful to study the work of some of your favorite artists. Convert their work to black and white and study how they solved the problem. See where they used their darkest darks and lightest lights. See how they grouped their darks and lights and arranged them for a pleasing composition. Group the like value ranges. See how many values they used. Do a study of it. Copy it.
It's also useful to take photographs (black and white) and a black marker and separate your light and dark value. Squint.