hey hey...
after taking a few run overs on your animations I have a few critiques and suggestions.
your going to need some good imagination, or a big mirror in order to pull off majority of the animations that you do.
-jumping-
* naturally when you jump, your body lowers to the ground, and you lean forward slightly. Either your arms lift backwards or outwards, and when you are ready to jump. Your body lifts, your arms are throw upwards, and you push from your heel and off your toes. Normally when you jump your body has to slow down in mid air, before it goes downward. EX : you SOMEWHAT hover for .5 to 1 second in midair before you actually start falling. When you land from a jump, you dont really lower to the ground as much. your shoulders drop fast but not always your forearms and hands ( incase you were doing something like shooting a basketball )
your jump has no build up of strength, no floating from the gain of gravity, and no strength resistance from when you land. Try having a friend jump up as high as he can and maybe as if hes reaching for something. Have him do it a few times so you can get the gestures down.
-Walking Trip-
when you walk, your spine subtly turns left and right as they sway in unison with your arms. Your body moves up as your front leg moves back from under you. When your front foot touches the ground, your body SLIGHTLY struggles to relieve the weight. Along with moving up and down, your body also sways to the left and right as you try to maintain balance on one leg as you walk.
When you trip, your body leans upward and forward and onto their toes as you fall. your arms flail into the air and your back leg tries to recover by swiftly going in front to catch you. When you trip or fall, your body about 95% does not fall flat on itself. It usually tries to reach an arm out causing it to twist and turn and when you hit the ground your body tries to compensate with that sideways landing with the weight of your other arm going downward as well.
again, another good idea is try and walk and purposely trip yourself without anticipating it. you may have to do it over and over, but Im sure eventually you'll get it