This sounds obvious but is the most important thing. Using the wrong pan or knife can be time-consuming, make life difficult and even sometimes be dangerous but here’s the thing: You need a lot less stuff than you think:

• A good sharp cook’s knife with a 8-10” blade. You are more likely to cut yourself with a blunt knife believe it or not so keep it sharp
• A small sharp paring knife
• A good long bread knife
• A sharp thin long carving knife
• Scissors
• A small sharp knife for cutting fruit etc
• A peeler. You can do this with a knife but why make extra work for yourself?
• Pans. You get what you pay for (more or less) but avoid aluminium – there’s a reason they’re cheap. Stainless steel is cool because they go on the heat but you can also put them in the oven. Don’t go for wooden or plastic handles – plain steel is best. Enamelled stuff like le Creuset pans look cool but weigh a ton and cost a fortune. And they also always have a spout so the lid doesn’t fit properly.
• A casserole dish with a lid (le Creuset are really good at these – cast Iron ones are great because they go on the hob, the earthenware ones are good for the oven but don’t go on the heat)
• Gratin dishes of different sizes – earthenware
• A cheese grater – the box type that has different sized holes on different sides
• Roasting tins. These are either steel or aluminium. You get what you pay for but none are that expensive so if you buy cheap ones then just be prepared to chuck them when they are spent.

That’s about it