How to Care for a Newborn, 1254

Queen Mary Psalter, BL Royal MS 2 B vii, f. 314v (1310-20)

“After the woman has delivered the child, you should know how to take care of the child. Know that as soon as the child is born, it should be wrapped in crushed roses mixed with fine salt… And when one wishes to swaddle [the baby], the members should be gently couched and arranged so as to give them a good shape, and this is easy for a wise nurse; for just as wax when it is soft takes whatever form one wishes to give to it, so also the child takes the form which its nurses give to it. And for this reason, you should know that beauty and ugliness are due in large measure to nurses. And when its arms are swaddled, and the hands over the knees, and the head lightly swaddled and covered, let it sleep in the cradle.” 

Aldobrandino of Siena, Regimen for the Body (1254)

Don’t worry: caring for a newborn is as easy as curing a ham. Just salt it with some aromatics, arrange it nicely, and wait for it to age.

How to Look Good on a Budget, c. 1280

Cantigas de Santa Maria

"Your clothing should be pleasing and fine, cut to your figure. If you have no expensive cloth to make clothing, then have it cut nicely from something less than the best, so that it looks good and you appear well dressed. If you lack good clothing, you should accept this: but let your shoes and footwear, belt, purse, and knife be the finest you can have... Be very careful not to wear unkempt clothing, for anything torn is lovelier by far: one appears ill-bred when wearing unkempt clothes, but torn ones simply cannot be helped. It never takes great skill to make something lovely look nice, but one who knows how to wear well what is not lovely appears pleasing and courtly."

Amanieu de Sescás, Enssenhamen de l'escudier (Instruction for a Squire), c. 1280

Stretch your fashion budget in a "distressed" tunic! The courtly look is all in the accessories.

How to Make Someone Die of Laughter, 13th century

Vein Man needs some armpit phlebotomy, stat.
BL Harley 3719, f. 158v (14th c.)

"Beneath the armpits are certain veins called "ticklish" which, if they are cut, cause a man to die of laughter." 

Richardus Salernitanus (13th c.?)

Tired of people not laughing at your jokes? You could just stab them in the armpits...

How to Treat Baldness, 13th century

"You're bald." "No, you're bald."
BL Royal 6 E VII, f. 197 (14th c.)

"By frequently rubbing your bald spots with ground onions, you will be able to recover the charm of your head." 

Regimen sanitatis salernitanum (c. 13th century)

This piece of advice is pretty cagey. Does the remedy actually cause your hair to return, or does an onion-greased scalp count as charming?

How to Make Bird Missiles, 13th century

Them's fightin' birds!
Luttrell Psalter, BL Add. 42130 f.17v (14th c.)

"Another kind of fire for burning enemies wherever they are. Take petroleum, black petroleum, liquid pitch, and oil of sulphur. Put all these in a pottery jar buried in horse manure for fifteen days. Take it out and smear with it crows which can be flown against the tents of the enemy. When the sun rises and before the heat has melted it the mixture will inflame. But we advise that it should be used before sunrise or after sunset." 

Marcus Graecus, Liber ignium ad comburendos hostes ("Book of Fires for Burning Enemies"!, 13th c.)

Revealed: the origins and operational tactics of Angry Birds. The text does not explain how you get the crows to fly against enemy tents, but my guess is you put them in a little avian catapult and aim it with your finger. 

How to Care for Your Teeth, 13th century

"This is how to keep your teeth: gather the grains of a leek, burn them with henbane, and direct the smoke thereof to your teeth with a funnel, as if smoking a pipe." 

Regimen sanitatis Salernitanum (c. 13th century)

When you can't brush, fumigate! Recommended by nine out of ten medieval dentists.

Ask your dentist about a commemorative tooth-necklace.
BL, MS Royal 6 E.vi (c. 1360-75)