koontz1973 wrote:And a filter can never be as good as doing it yourself in the end
That's where you're wrong. There's no inherent quality in only using a smaller set of tools. In other words, the method doesn't matter, only the end result.
Filters are not inherently bad... only when they're used in a way that makes it obvious that a filter has been applied. I know you hear a lot of comments like "that looks like a simple photoshop filter" but they usually refer to situations where a new mapmaker has used a filter in an inappropriate way.
However, filters can be used effectively, if you know how to use them. Even basic filters. For example, I use gaussian blur all the time and it's one of the most basic filters available. And more advanced filters can be very useful, if they are not the only tool you're relying on.
In other words... using filters as a crutch to cover up sloppy work = bad, using them to improve the quality of your work = good.
Anyway, if you have problems installing G'MIC, let me know and I can help you. I think it could be beneficial for you in this situation, it contains multiple filters that can be used very effectively to get the kind of effect you need. Especially if you combine them with different layer modes.