As explained in the chapter on angle advantage, the defender usually has an advantage when we peek a corner, and can often see us first. To deal with this, and minimize the advantage, we use different peeking techniques. The different terms are often overlapping, and some are used by different people for the same thing, especially shoulder peeking vs jiggling. I will use what I think is correct, but be aware that these terms may be used differently by others.

Novice

Short peek/ standard peek

Short peek is the most standard peek, and is effective in most situations. The goal of this peek, is to move around the corner as fast as possible, then stop while showing as little of our own body as possible while seeing as much of the enemy as possible. This leads to the shortest possible time between showing ourselves until we are ready to shoot. This peek requires good knowledge of the different angles and spots of the map. As we want to get out as fast as possible, we should move a step before peeking. This is faster than starting at 0 velocity. In most situations we need to peek silently, so we want to practice hitting as close as possible to the maximum speed without making a stepping sound.

Wide peek/ swinging

Wide peeking is simply moving wide when you peek a corner. This technique is mostly used in order to move past the enemy’s crosshair, so that they have to readjust before firing. This slight moment can give you an advantage to fire at them before they have readjusted.
When wide peeking, we often want to move closer to the corner rather than further away. This may seem weird if you have just read the post on angle advantage, and how this increases the time they are able to see us while we cannot see them. However, by moving closer to the corner, our wide peek creates a larger angle for the enemy to readjust their crosshair, which as mentioned, often is our reason for choosing to wide peek.

Shoulder peek

Shoulder peeking is showing only our shoulder to the enemy before moving back behind cover. Our goal is to bait them into shooting.
Shoulder peeking/ shoulder baiting is very useful against AWPers, to bait out the shot, before taking the angle ourself. Shoulder peeking is also used to learn information such as enemy position and what gun they have.
Shoulder peeking can be done both close to the wall, or far away from the wall we are peeking. Peeking closer, it is easier to know exactly how much of our body is seen by the enemy, while further away they have less angle advantage and we can more easily start jiggling or pre-firing.

As we move quite slowly, there is some risk to shoulder peeking. To minimize this, we can shoulder peek with the knife out to move faster.

Be careful if shoulder peeking far away from the wall with the knife out, as the enemy may easily take a step out and you will have nothing to defend with.

Crouch peek

Crouch peeking can be beneficial in some situation. Crouch peeking is especially strong with AWP, but still valuable with rifles and pistols as well. Similar to the widepeek, crouchpeeking leaves us a bit vulnerable, and we do have to commit to the fight. There is usually no backing out from a crouchpeek.

Intermediate

Jiggling and pre firing

Prefiring and jiggling is basically a wider shoulder peek, so that we can spot them shortly before falling back behind cover. Our goal is not (only) to bait out a shot, but to spot them and even shoot at them, while being a hard target to hit.
Jiggling is very useful if there are multiple spots a player can be, but we are not able to clear them one by one. This may be vertical spots, 50/50 angles etc. By jiggling, we can spot where the enemy is located before going into any other type of peek.

When Pre firing, we want to move as far away from the corner as possible. This makes our peek have a smaller angle and the enemy less angle advantage. Similarly to how we wanted to increase the angle for our enemy (and our self) when wide peeking, we want to decrease the angle as much as possible when we are pre firing. This way we need to move our crosshair less, and as we are prefiring we are not going to move it at all, we should be more likely to hit our target.

Advanced

Shift peeking

Shift peeking a corner should only be used if we have the angle advantage. If we don’t have the angle advantage, this technique is too slow. If we know that we have the angle advantage, shift peeking can be very effective. We should then be able to see their arm before they can see any of our body.

Jumpspotting (for info)

Jumpspotting serves the same purpose as jiggling, but is done while jumping. The goal is to be a very hard target to hit, while getting the information of where the enemy is located. Jumpspotting should be done with a knife out as there is no chance that you will be shooting anyone with this technique. There are mainly two different types of jumpspotting you need to know. First is jumpspotting a wall, peeking out to the side of the wall, second is jumpspotting over something usually spotting over a box.

When jumpspotting over a box, we also want to be as hard as possible to hit. This can include techniques such as running sideways before jumping, to not hang in one place in the air. We can also crouch before jumping, to not jump as high and showing less of our body. This also make no landing sound after the jump if we release the crouchkey mid-air.

Jump shooting

Jump shooting is arguably a sub genre of jump spotting, where the goal is to shoot the enemy while you are mid air. The technique relies on you being very hard to hit, while being able to deal a little damage, or a chance at a kill. This technique is somewhat effective with shotguns and the scout, while other guns rely on you being extremely hard to hit.

Jump peeking

Jump peeking is different from jump spotting. Jump peeking is a way of peeking into a fight. Our goal is to be hard to hit, and give our self time to land our shot. This technique is mainly used with AWPs. To effectively use this technique it is recommended to experiment with distance to the wall, to learn how far your jump peek should be to be effective. If you have the entire arch in the open, the opponent may have too much time to shoot you midair, while if you land the same spot as a regular peek, you may not throw their aim off enough.