My favorite tip and one I use EVERY day almost all day long:

Image Ready (IR)is bundled with PhotoShop and does almost everything PhotoShop does but takes less system resources. Beyond that, you can manke animated banners in IR and what I love best, it has a great utility to slice images and creat the html for it. You can combine/delete slices, specify some slices to be ge gif, animated gifs as well as jpeg. Makes a great shortcut especially when making larger banners and hpa/fpa