I can't speak for other artists, but often in my case artwork is never really finished, it's just done "enough," or in danger of too much re-working. I can recall a comic I did called "Bleed for Me" that I re-did several times. Still not sure if the end result was the best. But it's either redo it again or go on to other things from there.
Case in point, I find myself still thinking about or re-reading those awful dog stories I went over in a previous entry. Partially because it's like a different person did them and I am trying to recall the state of mind I was in when I did them...besides being young and confused (as opposed to older and confused like I am now). Also looking at the art and writing and wondering if it were done better, could it work now? Even though at the very core it's about dogs being killed in many ways. Alien dogs, okay, but dogs drawn in an intentionally cartoony way.
One thing on my eternal list is a manga-style series, I just need a story, perhaps this could be it. I've seen some good horror manga and also some surreal humor ones (I LOVE FLCL!). Could be, could be...
Anyways the spaniels keep finding their way into my sketchbooks lately. One of their aspects is that they breed like rabbits, so I offer both apologies and none for the following: