(1) Have you somewhat to do tomorrow, do it today. 

(2) If it is not right, do not do it; if it is not true, do not say it.(If it is not broken, do not fix it.). 

(3) If you want a thing done well(sentencedict.com), do it yourself. Napoleon Bonaparte 

(4) If you would have a thing well done, do it yourself. 

(5) If you want a thing (well) done, do it yourself. 

(6) He who has done ill once will do it again. 

(7) If wise men play the fool, they do it with a vengeance. 

(8) I think we should do it this way.

(9) I can't do it anymore.

(10) Think twice before you do it.

(11) Everything stays the same, I just can't do it.

(12) This is how you do it.

(13) It's my turn to do it.

(14) This is the way you should do it.

(15) That's how you do it.

(16) I'll do it my own way.

(17) This is how you should do it.

(18) We will do it ourselves.

(19) Are you sure you can do it?

(20) Do it slowly and carefully.

(21) Don't mint at it;do it at once.

(22) How can I possibly do it?

(23) Why did you do it?

(24) 'I'll do it[http://Sentencedict.com],' she offered.

(25) She resolved to do it at the first opportunity.

(26) How should I do it?

(27) Watch what I do and how I do it.

(28) I can't do it, I can't.

(29) If you would have a thing well done, you must do it yourself. 

(30) I hate to see things done by halves-- If it be right, do it boldly, --if it be wrong, leave it undone.