I was trained to develop concepts to be followed by digital recreation. You should almost never start a design project by playing with software filters in hopes that you accidentally create something you respond to with "Hey, that looks pretty cool!" Effective artwork starts in your medulla oblongata -- not on your computer screen.
I stand by that. In fact, never, never, never use a Photoshop filter on an entire photo as a finished product. It's not just a waste of time on browsing, it's cheesy. Adobe developers created Filters (aka mathematically generated fills and fractals) because they could. It doesn't mean you have to use them.
But every once in a while, you get a client that doesn't know what they want, so YOU don't know what they want. This is one of the rare cases I would use color manipulation presets in order to present some comps without wasting time going in the wrong direction. Start with carefully selected images (most likely from the client), and apply ATNs to generate a few options to quickly display for your client. You should be able to narrow down the scope of the need for that project. Refer to Photoshop Support if you're new to action scripts.
I recommend these basic Photoshop Actions:
At this point, you are still far from done. But at least you will save yourself from designing something that the client would never want. This is not to say that all projects are going to be dictated by what the client feels they want -- because sometimes, what the client thinks they want isn't necessarily what they actually want. Tip: If you're planning on going with a "comic" theme, don't use the Action for the final product. These are for quick idea comps only. Be sure to explain this to your client. Besides, you wouldn't use a downloaded Action that you couldn't create on your own, would you!
Remember that some Actions generate 100+ steps -- too many to undo with Command+Z (Ctrl+Z) -- so be sure to save Snapshots and create presentation comps on a separate canvas. Every image is going to be work differently, so apply Actions wisely. There is no substitute for the creative process.
Me ke aloha,