“You’ve made your bed, now you’re going to have to lie in it”.
Most people lie in an unmade or turned-down bed, no?
“I’m head over heels for her!”
So what? I’m head over heels for most people.
“Made” as in manufactured, not as in straightening out the sheets.
Perhaps you made your bed … poorly, and will now have an uncomfortable night.
Roddy
“Look before you leap” doesn’t make sense because “He who hesitates is lost”.
Beds which are poorly made as in “straightening out the sheets” can also be quite uncomfortable. My mother likes her blanket/sheet up to her eyebrows; I like mine low enough to take one arm out comfortably without folding the sheet; I’ve known people who quite literally “slip themselves into the envelope” when they get into bed under a minimum of three woolen blankets (that’s in the middle of summer), and others who cannot conceive of sleeping under anything heavier than a single bedsheet.
You have that ass-backwards.
and while “The squeaky wheel gets the grease” “The quacking dock gets shot”.
This is why you should never look to idioms for advice.
Out of sight, out of mind vs. Absence makes the heart grow fonder
Pen is mightier than the sword vs Actions speak louder than words
What you see is what you get vs. Don’t judge a book by its cover
Many hands make light work vs. Too many cooks spoil the broth
Birds of a feather flock together vs. Opposites attract
Just to name a few.
One that always bugs me: “I could care less” to mean “I don’t care”.
Preposterous. (Look it up, if you want, etymol.)
The two proverbs are used in different contexts. Sometimes it’s best to pause before doing something to think it out; other times, waiting too long can cause you to miss out. The two phrases are always used in context of a situation, one to say “be cautious”; the other to say “don’t wait” and are used by the speaker to indicate his own feelings on the matter.
So they make perfect sense.
You can’t have your cake and eat it too.
I don’t know how you can eat it if you don’t have it.
Actually, the quacking dock gets looked at closely; there might be some poor duck caught under it. 
I like the Japanese counter to “squeaky wheel”: 出る釘は打たれる (The nail that sticks up gets hammered down.)
That’s another one that makes more sence turned around.
You want to eat your cake but still have it.
Throwing the baby out with the bath water should mean you are blind because babies look nothing like bath water. “Hey ump! Stop mistaking babies for bathwater and call strikes!”
Look at what the cat dragged in should mean you stink like something that has been dead at least a week.
A bird in the hand is worth two in the bush should mean you made a bad trade. A bird in your hand must be a pigeon or smaller, but a bird in the bush might be a turkey.
Why isn’t spilt milk worth crying over? What if you live in Ethiopia?
If the grass is greener on the other side, water your damn grass.
I’ve always taken this to mean “You can’t eat your cake and still have it (sitting there uneaten).” That is you can either have uneaten cake, or you can eat the cake, but not both.
Roddy
That’s what it means, but it always sounded odd to me. As wolfman said, it sounds a little better the other way round.
I’m guessing it’s origins predate mattresses bought at the store…
“Stuck between a rock and a hard place” vs “give me a long enough lever and a firm place to stand and I can move the world.” The rock shouldn’t be that hard to move.
Behind the 8 ball is a great place to be if you’re playing 9 ball.
“Like a cat on a hot tin roof” should mean “he fell down.”
“Bringing a knife to a gun fight” is especially handy when the ammo is gone, and was the de-facto method of warfare during the flintlock period. After you fired once, you went in with your bayonets.
“When life gives you lemons, make lemonade.” Life had better give you sugar as well otherwise it’s going to taste like shit.