A dictionary of Proverbs (Oxford Paperback Reference)

half-done see FOOLS and bairns should never see half-done work.
halfway see a LIE is halfway round the world; do not MEET troubles halfway.
hall see it is MERRY in hall when beards wag all.
Don’t HALLOO till you are out of the wood
Do not exult until all danger or difficulty is past. Halloo literally means to shout in order to attract attention.

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  1770 B. FRANKLIN Papers (1973) XVIII. 356 This is Hollowing before you are out of the Wood. 1800 A. ADAMS Letter 13 Nov. (1848) 381 It is an old and a just proverb, ‘Never halloo until you are out of the woods.’ 1866 C. KINGSLEY Hereward the Wake I. iii. Don’t holla till you are out of the wood. This is a night for praying rather than boasting. 1936 ‘E. C. R. LORAC’ Crime Counter Crime i. Don’t halloo till you’re out of the wood. I’ll bet my head to a china orange we shall have trouble before to-morrow night. 1947 M. LONG Dull Thud x. 99 ‘Don’t whistle till you’re out of the woods,’ I advised her. ‘The investigation hasn’t even begun.’ ■ peril; trouble
  

halved see a TROUBLE shared is a trouble halved.
When all you have is a HAMMER, everything looks like a nail
Principally known in North America.

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  1966 A. MASLOW Psychology of Science (foreword) x If the only tool you have is a hammer, it is tempting to treat everything as if it were a nail. 1981 New York Times 11 Nov. D13 ‘There is frequently a lack of understanding of what power is—I’ve got power, therefore I’m right,’ he said. ‘When you’ve got a hammer, everything looks like a nail.’ 1989 PC Magazine 14 Mar. 78 That kind of crude misapplication of PCs and PC software —the computer world’s equivalent of the old saw that ‘when all you have is a hammer, everything starts to look like a nail’—means death for productivity. 2002 Washington
  

Post 7 Apr. H7 It’s a waste to use $480 worth of Office suite for such simple work. But it’s not a surprise either. To paraphrase what others have said: When Microsoft Office is your only hammer, pretty much everything begins to look like a nail. Or a thumb. ■ necessity; ways and means
hammer see also the CHURCH is an anvil which has worn out many hammers; (verb) the NAIL that sticks up gets hammered down.