bro its not toast why did you butter it like that? Just use the size of a pea or an "x", don't spread it thin or at all. And as long as it isnt conductive TECHNICALLY (within reason) you can't use too much. As long as you aren't you know, retarded.
A pea sized dot in the centre is all you need. I like to do an x which is viable too but don't take it right to the edges and keep it thin. A little goes a long way.