As a general rule never take your whole fee in advance, nor any more than a small retainer. When fully paid beforehand, you are more than a common mortal if you can feel the same interest in the case, as if something was still in prospect for you, as well as for your client.
He who represents himself has a fool for a client
No client ever had money enough to bribe my conscience or to stop its utterance against wrong, and oppression.
Talk to the jury as though your client's fate depends on every word you utter.