The first principle of animation is squash and stretch. This principle is a very useful way to add additional weight and flexibility to objects, especially when creating work that is more stylised and cartoony. The volume is kept the same, so for example, if you had a cube at 10cm x 10cm you would need to keep the volume at 10cm squared, even when squishing it down. Squash and stretch is even used in realism, with parts of the body squashing and stretching when humans move, though the further you exaggerate this effect the more cartoony your animation can look.

The next principle is anticipation, which is a key feature in any form of storytelling. Most movements look unnatural if there is no build-up towards them, as an example to swing a bat there needs to be some preparatory movement instead of just instantly swinging it for it to look more natural. Anticipation can be exaggerated heavily to really give an audience an idea of what is going to happen next.

Principle 3 is staging. This is similar to composition, in that you need to be able to draw the audiences eye towards what is important in the scene. The most important object in the scene should usually move the most, with less important objects staying stationary or moving only a small amount.

Straight ahead action and pose to pose are the fourth principle. Straight ahead action is the method of animating from the beginning to the end in a linear fashion. Pose to pose is different in that you first map out the key poses in the animation, later adding in the in-between frames. They have different strengths and weaknesses, with straight-ahead action often looking more fluid whilst pose to pose gives the animator more control over how the result will look.

The 5th principle is follow-through and overlapping action. This principle to me seems the opposite of anticipation, with importance on what happens at the end of the animation instead of the beginning. Most motion does not end instantly (as an example to stop running you usually cannot just go from fully sprinting to not moving at all). You need some animation after the main movement has finished, for example, the hair continuing to move after a character has jumped and stopped.

Slow in and slow out is another principle of animation, meaning that you need to ease in and out in terms of speed. Generally, things accelerate to their fastest speed over time, then when they stop they decelerate until they fully stop completely. This can be seen in cars, people running, bikes, etc. To do this an animator can choose how many frames they use – for example, they could initially have a start and end frame, and if they wanted the object to slow in the middle they could assign more frames to the time when the object is in the middle.

The 7th principle is Arc. This means that many objects follow the rules of gravity – they do not travel in straight lines through the air and generally move in an arc through the air as they are pulled down by gravity. This can be a useful way of showing the weight of an object, or weather conditions as they can affect the arc of movement that an object would take. You can go against this intentionally to create erratic, unnatural movements in some cases.

Principle 8 is secondary actions. This means that to add realism to movements, there are often subtle minor actions that also take place though are not as noticeable. These minor actions contribute overall to how fluid the animation will look. As an example, when people walk they don’t just move their arms and legs, they use most parts of their body even if only slightly swaying their hips, bobbing their heads, flicking their heels, etc.

The next principle is timing. This can be used by choosing an appropriate speed for each object, and objects cannot travel faster than they would in real life if you want your animation to look realistic. This can be exaggerated to an extent and remain somewhat realistic but should generally be followed. Timing is useful to help the animator convey how a character is feeling.

The 10th principle is exaggeration. If your animation is too focused on realism this can be boring and lacking in motion. To add some flair to it you can push how far you take the movement, beyond what is completely realistic to make the animation far more entertaining. Most children’s cartoons heavily used exaggeration to add character and personality to objects and characters, for example, if a cartoon character is surprised about something you can animate the eyes to literally pop out from the head.

Solid drawing is another principle that can be used to ensure that you understand perspective, lighting, anatomy etc. This is useful to maintain consistency throughout your animation, as it can be confusing to audiences if you are not keeping objects consistent in size or position unintentionally. Characters should however not be completely mirrored, as very few humans are perfectly symmetrical and so some minor changes from left to right can help characters look more normal.

The last principle is appeal. Characters, objects and settings need to appeal to audiences or no one will be interested in watching your animation. Adding personality and interest to these can be a good way to interest audiences. This takes a lot of skill to understand as you must understand not only your own tastes but those of your target audience as well. This also does not just mean only in making characters likeable – villainous characters can be appealing whilst not being meant to be likeable to the audience. It is more about being interesting than “good”.