I was talking with this girl last night, and the expression “make do” came up. I’ve always spelled it “do”, at least, however, she used “due.”
On further dicussion, it came to light that she’d been discussing the same thing with her roommate with no resolution.
Anybody got a history on this expression that’ll settle this? It’s gonna bug me til I get an answer…
–John
I would go with “make do”. There is an expression “Make do, or do without.”
“Make due” can be correct in certain contexts, but I work in a library, so we’re “making due” all day long.
In the Royal Navy there is a commonly used expression called ‘make and mend’ which is nowadays used to indicate a rest break.
It is short for ‘make do and mend’.
It comes from sailship days when ratings were ecused work, ostensibly to maintain their kit and clothing.
Nowadays if you have been on duty in the middle watch 0.00hrs to 0400hrs you normally are given the afternoon off - a make and mend.
New Shorter Oxford English Dictionary
There is no entry for make due. make-do (with the hyphen) is a noun meaning “a temporary expedient” or an adjective meaning “characterized by makeshift methods.”
Of course if you don’t say things with a silly american accent, then there is no confusion. Due and do are pronounced quite differently. 
To “make due” would imply that something would be forthcoming, as the librarian impishly pointed out above. It would make more sense to say “come due”, since being due is a pre-arranged condition of lending. And what that has to do with eking out whatever you have to eke escapes me.
To “make do” is one of those strange mental contractions, in which a specific article is implied. As in, “the recipe calls for two teaspoons of vanilla. I only have one, so I’ll have to make [one] do [the job of two].”
In other words, to make do is to say that we have to make whatever is available to us do whatever we need it to do.
As someone who is 6’5", I’ve never had the adverb “impishly” applied to me before.
I’m deeply honored.
An old saying:
BobT, not only was your observation impish, but you’re cute a bug yourself.
In a nice way, I mean.
Of course, “make doo” is entirely different.
I thought it, but I didn’t wanna be the one to say it.