Several posts back it was mentioned that adding lots of styles and fonts to your PS or PSElements can slow the system down. The same applies to brushes and actions as well.
I never put these files in my Photoshop system folders.
I install a few styles and actions that I use a lot, and the others I install, use them for a while and then remove them from my "styles window" or the actions window" this is just removing them from photoshop, and as long as you have them saved (i am like Jenn -- i have all my actions, brushes, styles, gradients, patterns and filters saved in a folder called Photoshop add-ons) you can go back and load them as you want to use them.
I purged many of my fonts, since I was crashing half them time when I tried to use the text tool or do my journaling. I only keep a few that I use often (as well as all the presets the system came with) and I have not had the problems crashing I used to have.
for people who use programs that dont have "styles", some designers will include the .png file of glitter or felt or whatever it may be. You would use them like a clipping mask, layer of the item you want "glittered" and then the glitter layer on top. I like to make a duplicate layer of my item, and clip the "glitter" to that. after the clipping, I have two layers, my original, and a layer the shape of my original with the "glitter" I can then play around with the opacity, color, and blending.
I used to use lots of actions to do things when I first started scrapping. I have found that many of those I learned to do myself, and they took a long time. Actions have come a long way and the newer actions out there are so fast. I still like styles, since all I have to do is click one button -- but a great black and white action is a wonderful tool to have.