AutoCAD 2006/07 has a new feature called Separate Hatches. This new feature comes in handy when you want to just hatch your boundaries all at once, then after, apply different hatch patterns to each separate hatch. Pretty simple little feature but does help!!
Another enhancement with Hatches in the ability to separate previously "Grouped" hatches. You can double click you're hatch to open the Hatch Edit dialog box, then simply check the separate hatches check box to separate the hatches again.
One thing that have always bothered me about hatches is sometimes the custom hatch patterns can be extremely slow. Usually you'll notice this when you try to move custom hatch patterns. So a little trick I use is to simply create a block of the hatch. If you quickly make a block of the slow hatch pattern you can quickly move the hatch around your drawing, then when you need to edit it you can easily explode the block back to a hatch and work as normal.