Cannot agree enough with this.
I probably do effects wrong but if I get the sound I want then it's right for me. Since I bought a Line 6 X3 I've found the answer to avoid mud/mush is the ability to run two signal paths together, one with your disired effects and the other clean and punchy. No matter how dirty the effected channel gets the low mid punch is always there, unless of course you don't want it to be.
The other I do, which relates to the quoted post above, is when creating an effect at home with the Line 6 is to copy that tone to a whole bank or two on the pedal with little tweaks to the amount of effect and EQ, then at rehearsal with the band at volume I can just tap through the patches to find the best one, it really helps to be able to a/b like this, then copy the best patch and make minimal tweaks to that copy to fine tune, you still then have the original 'best patch' to a/b with. Good sound doesn't have cost the earth.