You don’t taste as you go.
Result: The flavors or textures of an otherwise excellent dish are out of balance or unappealing.
You don’t read the entire recipe before you start cooking.
Result: Flavors are dull, entire steps or ingredients get left out.
You make unwise substitutions in baking.
Result: You wreck the underlying chemistry of the dish.
You boil when you should simmer.
Result: A hurried-up dish that’s cloudy, tough, or dry.
You overheat chocolate.
Result: Instead of having a smooth, creamy, luxurious consistency, your chocolate is grainy, separated, or scorched.
You over-soften butter.
Result: Cookies spread too much or cakes are too dense.
You overheat low-fat milk products.
Result: The milk curdles or "breaks," yielding grainy mac and cheese, ice cream, or pudding.
You don’t know your oven’s quirks and idiosyncrasies.
Result: Food cooks too fast, too slow, or unevenly.
You’re too casual about measuring ingredients.
Result: Dry, tough cakes, rubbery brownies, and a host of other textural mishaps.
You overcrowd the pan.
Result: Soggy food that doesn’t brown.
You mishandle egg whites.
Result: The whites won’t whip up. Or, overbeaten or roughly handled, they produce flat cake layers or soufflés with no lift.
You turn the food too often.
Result: You interfere with the sear, food sticks, or you lose the breading.
You don’t get the pan hot enough before you add the food.
Result: Food that sticks, scallops with no sear, pale meats.
You slice meat with―instead of against―the grain.
Result: Chewy meat that could have been tender.
You underbake cakes and breads.
Result: Cakes, brownies, and breads turn out pallid and gummy.
You don’t use a meat thermometer.
Result: Your roast chicken, leg of lamb, or beef tenderloin turns out over- or undercooked.
Meat gets no chance to rest after cooking.
Result: Delicious juices vacate the meat and run all over the cutting board, leaving steak or roast dry.
You try to rush the cooking of caramelized onions.
Result: You end up with sautéed onions, which are nice but a far cry from the melt-in-your-mouth caramelized ideal.
You overwork lower-fat dough.
Result: Cookies, scones, piecrusts, and biscuits turn out tough.
You neglect the nuts you’re toasting.
Result: Burned nuts, with a sharp, bitter flavor.
You don’t shock vegetables when they’ve reached the desired texture.
You put all the salt in the marinade or breading.
Result: Fish, poultry, or meat that’s underseasoned.
You pop meat straight from the fridge into the oven or onto the grill.
Result: Food cooks unevenly: The outside is overdone, the inside rare or raw.
You don’t know when to abandon ship and start over.
Result: You serve a disappointing meal. And you know it’s disappointing!
You use inferior ingredients.
Your poached eggs aren't pretty
Result: The typical botched poached egg is tentacled, scary, tough, overcooked.
Your gravy is lumpy
Result: Lumpy gravy. Next time, whisk wisely. Meanwhile, here's a fix.
Your mashed potatoes are gluey
Result: Gluey mashed potatoes. Next time, watch the cooking time and drain well.
You Burn the Brown Butter
Result: Dark and bitter butter. Next time, pay attention to the visual cues.
Your bacon is burnt and crinkly
Result: Burnt and crinkly bacon. Next time, bake your bacon.
Your Green Veggies Turn Brown
Result: Drab veggies. Next time, baby them and they will stay vibrant.
Your Salad Goes Limp
Result: Soggy salad. Next time, consider three important factors.
You Incinerate Chicken on the Grill
Result: Charred skin and rare meat in the thickest part of the breast.
Your Hard-Cooked Eggs Are Icky
Result: A rubbery, chalky, green-gray hot mess! Next time, heat slowly and cool quickly.
Your Turkey Burgers Are Parched Pucks
Result: A dried out burger that sticks to the grill. Next time, add a little heart-healthy fat to help the meat stay moist and juicy.
Your Rice Gets Gummy
Result: Sticky, gummy goo. Next time, use more water.
Your Caramel Meets a Burnt, Bitter End
Result: Burnt, bitter caramel. Next time, a little water—and patience—goes a long way.
The Turkey Hack Job
Result: Your turkey platter resembles a crime scene.
Your Cookies Gain Unwanted Holiday Width
Result: Sad gingerbread men.
Via Cooking Light