1. Slow, painstaking prep: Chopping and peeling take up a significant amount of time and, while these tasks can't be avoided, it helps to know how to speed things up. Take peeling garlic, for example. Even with the smash method, peeling more than a few cloves starts eating up time. Try this method and peel an entire head of garlic in seconds! When possible, prep ingredients assembly line style, peeling each one before chopping. Or buy already prepped ingredients when doing so will save major time (like buying already peeled and cubed squash, for example).
2. Choosing the wrong knife Do you always find yourself using a paring knife? Knowing when to break out the big knife, as well as methods for using it efficiently are invaluable skills in the kitchen. And keep them sharp -- sawing away at a tomato just to break the skin is not how properly sharpened knives should perform.
3. Discarding leftovers unnecessarily: It can be a little heartbreaking to clean out the refrigerator and discover food that could have been great with last night's dinner. Start planning dinner from your refrigerator and swap already cooked ingredients for others on your list.
4. Misunderstanding how your appliances work: Ever try to cook pancakes on a pan that's not quite hot enough? Not only does to take forever for the pancakes to show any sign of browning, they don't end up tasting quite as good. Learn your stove's quirks and when a hot pan is an ingredient's best friend (searing meats, caramelizing onions, and reducing liquids). And of course, when to simmer down (melting chocolate, cooking scrambled eggs, and making rice).
5. Mistreating pots and pans: More of a long-haul tip, scraping your teflon pan with a metal spatula is guaranteed to shorten the life and functionality of your cookware. Few cookware items are made to be cleaned in the dishwasher, and it's helpful to read up on the proper care to help keep your pots and pans performing at their best.
6. Laboring too long over cleanup: We know, it's a challenge, but the best method to a speedy clean up is cleaning as you go. Also high on the list is rinsing plates, pots, and pans before food has a chance to adhere to them after a meal.
Read more: The Stupid Things You Do in the Kitchen and How to Fix Them at Lifehacker