This is just a an assortment of my thoughts about posing a character in Heromachine. If you're into more of superhero style or making cheesecake images, these might not be terribly useful for you.1) Is the pose physically possible and the body correctly proportioned?
There's only so many ways a person's joints can be arranged, after all. Try not to break your character's bones. Experiment a little with your own body and a mirror. This leads directly into part 2.
2) Is the pose a) static or b) dynamic?2a) Static
If the character is in a static pose, they should be able to maintain that pose for at least as long as they would pose for a photograph. I often try the pose myself to see if it can be done. Granted, many characters are much more flexible than I am, but it still gives me a good basic idea. Also consider that even if the pose is technically possible to achieve, it can still be awkward or uncomfortable in practice. This is especially true if you're using superhero material, fashion photography or anime as reference. I prefer a more grounded style, so I try to think of a pose that I personally could both maintain and move from.2b) Dynamic
If the character is supposed to be in the middle of movement, creating a believable pose is much harder. Use references! Remember that moving one part of the body, such as the fist during a punch, can result in changes in the rest of the pose as well. The movement of the punch also moves the shoulders, the hips, even the feet.
The character is in motion, so where will they be in a few seconds? Would they still be in motion or would they have fallen flat on their face? Are they in a position where they could comfortably begin some other action, or are they stuck?
Use clothing and background elements further enchance the motion. Capes, hair, air currents, superpower effects and such can really enhance the motion. If the character's hair lies flat on their head while they're running, that looks fake. If the character's fiery fist doesn't leave a fiery trail when they're punching, that's a wasted opportunity. Etc, etc.
Heromachine's basic options are very limited. Understand that you will have to use a lot of trickery to make a believable dynamic pose.
Basically the only image I have of a really dynamic pose:
If you want some really good examples, check out TheAnarchangel
.3) Perspective and foreshortening
If a character's pose has one part of their body closer to the viewer, that body part needs to appear larger than the rest. Duh. However, the size shifting will likely need to be gradual. A character reaching their hand forward will have a slightly larger-appearing upper arm, an even larger forearm and finally, a very large hand.
Remember foreshortening! If you don't shorten that reaching arm, it will just look like they have a giant arm that is reaching upwards.
If one leg is further away than the other, it will need to be smaller and thinner.
Shading can be helpful for creating a sense of depth! Basic rule: If we assume a forward-facing light source, items that are in shadow look like they're further away from the viewer.
Perspective takes practice and lots of fiddling. Try your best, then try again.
Here are some pictures where I tried to use some perspective.
4) Does the pose fit this particular character?
Simple question, really. Would this particular character take this pose? If they're a cool superhero, would they pose like a pinup model? If they're a fabulous, over-the-top character, would they pose like a boring normie? Just go in front of a mirror and think how you would pose if you were this character. If you can't think of a pose, do you really know the character yet? Even something as simple as a friendly salute or a hand on the hip can tell more about your character than three paragraphs of biography.
If the pose requires some other element to work, like a wall for them to lean on, or a rope to hang onto, it's a good idea to include that element.
5) Can I make the pose work with all the elements I want to include?
If your character has high heels, they won't be running terribly well. If the character has a cape or long hair, that might also pose issues.
Heromachine's options are also limited: You might not find the right foot items for a pose, or you might have to hide an awkward-looking shoulder behind a cape instead. Sometimes you want the character to wear gloves, but the only available hand items obviously have fingernails.
Many things can go wrong. Fix what you can, hide what you can't. If it is still impossible, return to the drawing board. You will have to make compromises! Either change the pose or change the character. These are hard decisions, but necessary ones.
Examples of my compromises:
A true dente di zhengiaro stance would have the sword more off-center, but the angled blades didn't work with that. I had to compromise and change the pose!
Smitty's original design had a chestplate and no loincloth. However, the chestplate didn't work with the angled torso, and the crotch looked really weird due to the pose of the legs, forcing me to hide it behind the loincloth. Also, the hands and feet were supposed to be more bestial, but the available options didn't fit the pose. I had to compromise and change the character design!