how can I improve my 60 sec poses?

https://imgur.com/a/9iNZXH0 I feel like I’m having trouble with viewpoints, like how when an hand is closer to you it looks bigger and a leg stretched out backwards looks smaller. I’m also having trouble with proportions. Advice needed!

What might help you is practicing ovals of different proportions. 

Right now it seems like you draw ovals of similar proportions for everything, and you draw them smaller when a limb is further away. However, because those ovals represent a shape that is turning, rather than something that is just straight up moving backwards, it doesn't quite give the right effect. 

Ovals with the same width but a different height would help a lot with suggesting the right shape, I think.

(And I think it'll also help with your proportions, since I think the main reason they can feel a little off is because of the lack of width on some of these limbs. The general height etc look pretty good imo)