Better slip with foot than tongue

Doing your best means never stop trying.

If you'd have it done, Go: if not, Send

You may talk too much on the best of subjects.

One thing is sure. We have to do something. We have to do the best we know how at the moment. If it doesn't turn out right, we can modify it as we go along.

We do our best that we know how at the moment, and if it doesn't turn out, we modify it.