Here's my second shot at your 'Minimum... The original doesn't turn into Latin Easily because of secondary meaning in Latin minimum - 'tiny', 'mean', 'sluttish'. And it doesn't work as 'only just enough;' that would be Vix satis. So here's my best attempt: it means "But do scarcely enough;" and the Romans would have hated it because they thought rhymes and chimes were uncouth.
AT VIX SAT FAC
Alternatively (but it might be a bit too elegant)
AT SAT PERFAC
AT is 'nevertheless' or 'but, however,' implying all the usual clichés can be taken as said, but now it is about to offer better advice. SAT PERFAC means 'get it finished adequately.' Perfac does not mean 'be perfect' as you might think, but 'finish it;' so perfectum 'done,' 'completed.'
If that's too abrupt here's a ready-made practical version.
This motto "It's done as soon as its good enough," was carved into one of the Civil War Buildings by the King's Carpenter. (Not the first motto which means "Live, so that you may live.")
SAT CITO SI SAT BENE literally 'Soon Enough if Good Enough' is one of the mottoes he used from 17thC French Emblem Books; and these have been published by a team at Glasgow University.
http://www.emblems.arts.gla.ac.uk/french/index.php