>>6372238Find references online, use manga panels and artwork (go beyond JJBA for more inspiration) and always test what that figure can actually do so you don't ham hand it just to push that arm into that angle. Use your own body as reference to see what looks natural as you try action poses.
Also, what I feel is really essential is just take a look back and see if the poses actually look good or if someone looks stiff. A lot of shots I've seen have really stiff poses come through by the user without them adjusting it before uploading. I always feel that person is either afraid to break the figure or didn't try to see how much range of motion that area allows.