There are three major categories of lock picks. Rakes typically consist of multiple sharp or flowing curves and are meant to manipulate multiple pins at once. Hooks are just the opposite, consisting of a single point, though there is a great deal of variety in how that point is designed. Hooks are meant to manipulate a single pin at a time. Profile picks are all sharp angles and may seem completely random at first blush. These are designed to recreate the profile of the key with minimal manipulation.
There are outliers that don't fall into the three main groups. Of those, most important are the diamond & ball picks. I'll cover those in depth. Depending on how quickly I put together the rest of this material I may cover more esoteric tools meant for specific locking concepts. We'll see!
The first tool many pickers will use is your basic medium hook. This is a perfect beginner tool because it's a bit clunky inside the lock, doesn't require a great deal of skill to get the best use out of it, but in its simplicity it remains very effective and often enjoys a place in the primary kit of any picker as their skill advances to the intermediate stage.
To best describe the medium hook's limitations, I'll explain the advantages of the Gonzo, so called because the head looks a bit like the nose of Gonzo the Great. Unlike the m.hook, the Gonzo has a rounded tip, allowing it to move more smoothly through the lock. Also, the tip extends just a bit higher than the m.hook, allowing it to better manipulate tricky high-low bittings. The Gonzo is beloved among many, if not most, advanced pickers and has taken the place of the m.hook in their primary kits.
The Long Hook is a bear. It is difficult to move through many keyways, can get caught inside the lock mid-pick and is generally just uncomfortable to work with. However - the extreme tip that causes all of those problems also allows it to set the most ridiculous high-low bittings. Though this pick rarely sees regular use, it has proved itself invaluable once or twice and so many pickers will keep it around, just in case.
The deep curve is the most widely borrowed member of a family of tools built around a specific method of picking. Personally, I've never cared for the Falle method of progressive curves, but there are people I respect a great deal who swear by it, so I'll leave it to them to fill you in. The deep curve, regardless of how I feel about the larger system, is an excellent tool. By allowing the belly of the curve to run along a low point in the keyway & rocking the pick into the lock, following the line of the pick head, you get a great sense of control and can easily manipulate difficult to reach pins in the back of the lock.
The most common notched hooks tend to fall, in height, somewhere between the m.hook & the l.hook. However, you can carve a notch into any pick you like and enjoy the benefits. Simply, the notch makes it easy to locate each pin inside the lock and in the rare situation where heavier-than-normal force is required you don't risk slipping off of the pin you are working on as you would with the Gonzo or m.hook. Finally, in locks with oddly shaped pins, such as Medeco's chisel tips, the notched hook allows you to manipulate them in more specific ways, such as rotating them.
I do not know Deforest's first name, though I've heard someone say it before. These days the picks named for him are more likely to be known as an "offset diamond" and "offset ball," but where possible I'll try to give these picks what I consider their proper names. The Deforest diamond is typically my second pick in a lock, right after the Bogota, which I'll cover in the rakes section. The angled tip of these picks gives the deforest deeper reach than your typical hooks and the added shape to the tip, whether ball or diamond, allow you some additional manipulation options. My primary use of the Deforest is to defeat the previously mentioned high-low bittings. The Deforest moves through a lock with ease, unlike the l.hook and can set the more extreme high-lows that the Gonzo can't quite reach. Though you will rarely find them in starter sets, a Deforest should be one of the first picks you make or acquire after you get comfortable with your initial tools.
There are other hooks and other single pin picks that straddle the line between hook and something else, but by the time you come across them, you'll be able to deduce their function.
I'm probably going to start some fights when I discuss rakes. I will be the first to admit that my tastes are sometimes non-standard, but I've tried countless tools and opened a lot of locks, so trust me. Then, when you find out I'm completely wrong and you don't open any locks, you'll have learned a valuable lesson about trusting experts on the internet.
I'll begin with the ever-popular "snake rake" or "c" rake. This diminutive, narrow profiled rake that is found, without fail, in every started set a new picker buys, is all but useless against decent locks. It will pop Master #3s like magic. It will stun and amaze and eventually, once you learn to use and love the other tools on this list, fall into disfavor and out of your primary kit.
Much more interesting is the Large S. When I first saw this tool I was told it was the German secret weapon. "Push, Push, Open!" my Dutch friend declared. I bought one immediately and found great success with it. The Large S is able to set more varied bittings than the C or the S.
The S rake is loved by a lot of people. I don't really tolerate it well and as such I'm probably not the person to describe it's best use. So I'm not going to! Ask almost any other competent picker though and I'm sure they can tell you why they like it. One note - this is a very common rake in starter sets and typically the first pick to break on a heavy handed newbie picker.
The L rake, however, I love. The L is the only rake I buy in bulk for classes and workshops. The most common profile you will find for an L rake is pretty timid, but can still do the job. While this pick will open a decent number of locks, I've found it's best use is in setting 7-9 cut pins. Apply light tension & rake low in the keyway to set the longest pins in the lock, then, increase your tension a little bit as you go back in with a Gonzo or Deforest diamond to finish the lock off. A basic, but very effective speed picking strategy. These aren't easy picks to make by hand, but can be well worth it so you can craft a more aggressive profile.
Most important in this list is the Bogota. Sole creation of Raimundo, this pick has been poorly reproduced by many of the major manufactures in the last 3 years. Unfortunately for the people buying the knockoffs, you can't just stick a Bogota rake on a popsicle-stick handle and expect it to work it's magic. Lacking the thin, bent handle of the traditional Bogota, they have dramatically reduced the efficacy of the pick. I cannot overstate the ludicrous quality of a well made Bogota rake. NKT, a British competitor at the Dutch Open (now LockCon) in Sneak, NL made it to the final table using nothing more than a set of Bogota rakes and popped one of the final round locks in 3 seconds as well. They double as tension wrenches, it's why they come in pairs. The basic method is to hold the rake like a trigger and "Shake like you've had too much coffee." Silly as it sounds, it works. Personally, I've developed a slightly different technique over the years, but still, it would not work without the bent handle. The Bogota is the only rake on this list that allows me to get a quick topography of the lock with a few simple swipes. Bogota + Deforest Diamond is how I won my Black Badge.
Then there's the W rake. The l.hook of the rake world. This unwieldy, aggressive rake is sure to get bound up in the back of your lock and it's thin connection between shaft and pick head means it will bend and break with heavy handed use. However, just like the l.hook, it has proved itself by opening a tricky lock, if rarely, and thus remains in use today.