My tutorial is very simple. I don't know any totally cool PSC trick, but I did discover this today...
Fade (Filter)
Usually, I would never use a filter in this contest because it doesn't take any skill to use. I also would avoid it because it looks so "filter-y" for lack of a better word. I always wished there were some sort of Filter Opacity slider or something.
Alack! There is something even better. After applying a filter, under the edit menu a new choice has appeared: Fade (whatever filter you just used). It allows you to not only make that filtery-look a lot less filter-y, but also allows blending modes to make it look more realistic. You can do this with every filter, and it usually creates a pretty neat artsy-effect.
For my fellow newbies, here is a visual guide to make this clear!
1) Open your Picture
we'll use this one, a recent contest.
2) Apply a filter from the filter menu
3) Go to edit -> Fade Find Edges... or hit (ctrl-shift-f)
4) play around with the blend mode and the opacity until you get what you want.
Find Edges Filter with exclusion
Photocopy Filter with normal
Sumi-E with luminosity
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Like I said, I don't think filters are appropriate for this contest. Usually on their own, they look stupid and fake anyway. You can create some cool effects, though, by playing with the hidden fade option. Note, you must do the fade immedietly after the filter-- you can't do it later.