“There was a suspicious-looking man in a black cloak! He was carrying a wicked-looking sword.”
The most important tool in the kitchen is your knife. To choose one that’s right for you, go to a high-end store like Williams-Sonoma that will let you handle all the knives. You want to test the heft and balance, and find a knife that feels comfortable and natural in your hand. After you’ve found your ideal knife, you can probably get it from a discount store for a better price.
A scale is very useful when you’re cooking. Instead of going through endless measuring cups (and having to wash them!), you can weigh everything out in a single bowl and reuse it to serve your meal if you like. My Salter scale has lasted over ten years.
Finally, an instant-read thermometer is indispensable for meat, poultry, and fish. I use a Thermapen. While you can certainly follow timing and visual cues, everyone’s kitchen is different. What I call “medium-high heat” might mean something else on your stove. If there’s anything I’ve learned over the years, it’s that cooking is an art, not a science. A thermometer will help you get closer to what you’re trying to achieve.