Any advice to help me form and shape stuff more uniformly? I get frustrated by recipes which call for the cook to shape or form little balls out of a dough or cake or biscuit mix.

The recipe will say something like "form into little walnut sized balls ... should make about 16". 

I always seem to end up with some larger than others. Individuals may look and taste good but it's a shame if they don't all look identical.

Anyone got any advice?
Use something that will help you measure the dough or mix uniformly. Some possible tools to co-opt for this task: Ice cream scoop, melon baller, measuring cups or spoons : all depending on size of course.

You should be able to get to where you can eyeball the size in relation to the tool you are using.