A good knife won't be cheap to buy but as the adage goes, buy right and you buy once. When it comes to choosing a knife there are lots of options and points to think about so take your time to weigh them up; especially as you'll likely have the knife for years to come. Have a browse through the guide and hopefully by the end of it you'll have a good idea of what type of knife you need (or more likely want).
There is no such thing as the perfect knife.
Keep in mind what you're wanting the knife for and pick one that's suited to the task.
There are tons of different types of knives and many are designed to tackle very specific tasks. A chefs knife (or gyuto) will perform most of your chopping, slicing and dicing tasks nicely due to their relatively thin edge but aren't ideal for tackling carving as repeated contact with bones would chip the thin edge. Likewise, a paring knife will struggle to cut up large tough veggies but will make peeling and chopping garlic a breeze. A carving knife would make short work of portioning up your Sunday roast and stand up to occasional contact with bone due to its thicker edge but would have you bashing your knuckles on the chopping board if you tried to use it for chopping veggies. So pick the knife or knives that are best suited to the tasks.
How experienced are you?
If you're just learning to cook or looking for your first handmade knives then you'll likely want to opt for a small selection of knives. A medium sized knife like a 7-8 inch chefs knife (or gyuto) will make quick work of chopping, slicing and dicing and will likely be your go-to for many tasks. You might want to team that up with a small knife like a paring knife for fiddly detail work like peeling. Whilst neither knife will process a fish as well as a good filleting knife, or portion up a roast as quickly as a carving knife, they will get you through a wide range of tasks.
If you're expanding your collection or an experienced cook then you might appreciate the extra leverage of a larger 9 or 10 inch chefs knife or the benefits of more specialised knives like boning, filleting or carving knives or single bevelled task-specific Japanese knives like the yanagiba and usuba.
Do you rock or chop?
Curved blade shapes that are more commonly seen in western style knives lend themselves to cutting in a rocking motion or slicing. Flatter blade shapes are typically associated with Japanese knives and perform better with push cutting/chopping.
Are you tough on your tools?
If you hate maintenance or are just a bit tough on your tools then you'll need to think carefully about the materials the knife is made from and the blade design.
Materials
Stainless steel knives are a good choice if you sometimes forget to wash and dry your knives straight after using them. Knives made from carbon steel will quickly rust if not washed and dried straight away. Whilst carbon steels may require sharpening more frequently, they are typically quite bit quicker to get back to shaving sharp than more complex stainless steels.
Certain handle materials can require more care and attention; for example, wood handles can't be left sitting on wet draining boards as they are likely to warp or split whilst manmade materials such as g10 are very durable but don't necessarily have the aesthetic appeal of natural materials.
Blade Design
If the knife has a very thin edge then it will be sharp but more prone to edge damage. If the knife steel has been taken to a high hardness then the edge should stay sharper for longer; keep in mind that as hardness increases generally so does the chance of the edge chipping. Getting the correct blend of edge thickness, steel hardness and steel type is critical to creating a knife that will perform well for many years. Many mass-produced western knives are around 55-57 Rockwell hardness which means they sacrifice some edge retention for the sake of ease of grinding and sharpening. Bespoke knives are often taken close to the maximum hardness the steel can reach - which is often 59 Rockwell (or more) for stainless steels and 61 Rockwell (or more) for carbon steels. This increases the difficulty of manufacture but the performance benefits are almost always worth it.
If you care for your tools then a hard, thin-ground carbon steel knife may suit you well. You'll typically get a lighter weight knife with good ease of cutting, high sharpness, a bit of flex and relatively easy resharpening. If you prefer a stiffer knife then a knife with more of a workhorse/thicker grind may be the way to go; they may not sail through tough veg as easily but will stand up to more abuse. For the ultimate combination of low-maintenance and durability you'll need to look for a thicker ground knife in stainless steel.
Mass-produced or handmade?
Handmade knives can be made to your exact use and taste using materials that balance performance and aesthetics. Whilst mass produced knives may be cheaper, if you want a knife that fits the buy right, buy once ethos then a handmade knife will fit the bill perfectly.