Really trick out your Dock
So far, I've talked a lot about customizing the Dock to make it look and act more as it did in earlier Mac OS X versions. But that isn't your only option. If you like the idea of a 3-D Dock but not the glass-shelf look, check out the options at LeopardDocks.com and Dockulicious. Both of these sites maintain dozens (if not hundreds) of alternate Docks that you can download and easily install with tools available from either site.
Instead of the glass shelf, you can have an iPhone-inspired Dock, a Dock that looks like a patch of lawn, one that looks like the icons are sitting atop a wood-paneled coffee table or even a Dock that looks like a tattered old pirate map. There are endless options ranging from stylish to whimsical to downright weird.
If you're not into themed Docks, you can also use DockColor to simply change the color of the standard 3-D Dock.
Make Stacks look and act consistently
In the Leopard 10.5.2 update, Apple responded to criticism about Stacks by making the feature optional. Users can now choose to display a folder placed in the Dock as a hierarchical pop-up menu of the folder's contents (as previous Mac OS X versions had done) rather than as a stack.
While this choice is an improvement, the update didn't address the major problem with Stacks: the changeability of their icons in the Dock. By default, the icon displayed in the Dock for a Stack shows tiny icons for the first few items (documents, image files, applications, folders, etc.) contained within the folder, stacked three-dimensionally, one in front of the other. The icons included in a Stack's representation in the Dock are arranged in alphabetical order of the items inside the folder.
Apple's intention here seems to be that a Stack icon will always reflect the contents of the folder that it represents. Unfortunately, this means that every time you add a new item to a folder represented by a Stack, the Stack's icon in the Dock may change. As a result, there is no real consistency for folders whose contents change often.
Even when folders don't have constantly changing contents, it can be difficult to tell which Stack is which without mousing over them to see their names highlighted. For example, two of the Stacks in the screenshot above look identical simply because they both contain folders and Word documents, and both happen to have folders within them whose filenames are alphabetically listed before any other items.
Although it doesn't change the overall behavior of Stacks, Stacks in Da Place is a great donationware tool for solving the problem of making each Stack look consistent regardless of its contents. It lets you select a single icon that will be perpetually displayed as the front icon in a Stack so you'll always know which Stack is which.
A great companion to Stacks in Da Place is one of several series of drawer-style icons for Stacks by Yasushi Chida (note that the majority of text on this site is in Japanese) that make your Stacks look like filing cabinet drawers or bins containing the icons of the items in the folder being displayed.