Hi, JoJo!
Experiment with different brushes. PS 6 comes with some fairly interesting ones (awful ones, too!) and you can grab free ones from many sites. Some of them are image based. To start with, check out
Adobe Studio Exchange Just make sure any brushes you download from there are for PS 6 and earlier. Because the brush engine changed dramatically in PS 7, a brush created for 7 won't work in 6.
Also, try painting on different layers, with different colors. Experiment with opacities, blend modes, etc. Use "texture type" brushes to create interesting texures...you can use more than one
On different layers, too.
You can also create custom brushes from any image, say, made by a dingbat font. Be sure it's in black & white, then select the image, Edit Menu > Define Brush, name your brush. It will appear at the end of your current brush palette.
Hope this helps! Let us know how you do.
PS brush technics 
Linear Mode
