Sometimes, it's good to leave the canvas blank for a while. I've done it several times. My craft lecturer at teachers' college gave me a canvas a few years ago and advised me to paint it white. Well I got my brother Marc to do it.
That canvas was blank for a long time. I eventually drew on it, but again it remained unpainted for a long time. The completed painting is now on the wall of my parents' home ( hopefully). But it was a process, it didn't happen all at once. So it's ok to leave the canvas blank.
There are times when I'm bursting with ideas, but still I feel unproductive because I cannot create anything. That's ok too. The wire has been calling my name and yes I've made a few pieces, that call has to continue and I'll continue to answer but that too will take time. Sometimes I have to step back and observe, sometimes I have to sketch and at other times I just play. Don't get me wrong even when I step back some type of play is going on in my mind, I'm just dancing to the rhythm of a different drum. So for now the canvas is blank and that's ok.