That's an interesting topic, and one I struggle with all the time.
I think striving for productivity is a continuous job that never gets done.
You can never get productive enough right?
You learn as you go and get more productive over time as you get more efficient in combating procrastination and better at managing things.
Getting things done is just getting things done, it needs no feelings, so I would say don't try to wait for a divine force.
Starting new projects is fun, getting new idea's is fun, finishing projects is harder and less fun.
I also start new projects all the time, but the things that get done are the things I dive into and just finish regardless of how I feel about them.
In most cases by the time a project needs to be finished the thing already is becoming boring, right? The design starts to feel average, you already have way more cooler ideas and now you also realize how mush needs to be done to actually finish this not so cool project anymore, etc.
The creation cycle has this difficult passage embedded in it.
We have the energy and vibe of the new wonderful idea, then the passage of planning and gathering intelligence and start working on it, and finally comes the most difficult part "finishing it" in a situation you realizes how much jet needs to be done and how little fun it is to actually do it.
Noting but negative counter forces in the end right?
If one gets in this difficult passage he tends to go and seek some relief in a new idea that gives him some energy and vibe, but then the whole cycle repeats right?
Eventually we end up with lots of unfinished stuff because this strategy cannot deliver a finished job.
So how can we break this cycle?
It's actually relatively simple, "seek no relief".
As hard as we may know this is true, there actually is no good remedy to combat the situation, it's just pulling the switch and look at what needs to be done and just do it.
So try to find comfort in the idea that this is the only way it works best.
The only thing that helps to balance out the situation is wanting the results harder than relief (seek no relief in short term but focus on the long term result).
The thing is, getting past this situation is most important to get to become a productive artist (I don't presume to be one myself).
But That's what one eventually wants to be right?
If one has set his priority's about what he wants, then he will get only relief when he gets it, right?
So do you really want to become a productive artist or is having fun in short term more important?
And if so, what type of artist, because there is lots of different artists and art, we have concept artist, character artist, 3D generalist, visualization artist, animators, independent short film makers, game artist, etc.
Anyways, getting things in focus is to set the priorities right and that in turn defines direction and knowing what to do next.
So it basically boils down to this;
Pull thet switch, ask right questions, set priorities, bang the head through that wall and get to the results you really want!
Hope this helps in any way?