An oval or round patch is unworkmanlike and does not wear well.
A thick edge on a joint gives an unworkmanlike appearance to the work.
But Sir Joshua's sketched leaves would indeed imply some unworkmanlike haste.
An unnecessary nervous fingering of the reins should be avoided, as, besides being most unworkmanlike, it irritates the horses.
No man ever came back to Marwood and said, "Sir, you broke my neck in an unworkmanlike manner."