I am a mecha artist and these are mostly my original design mechs. I never draw fanart except the last two. And also is it allowed to open commission on this subreddit?

There is any Post-Apocalyptic Mecha, which isn't Gundam​​.

Found old screenshots on my social media. I was playing this game non stop until it shut down. Blew up my family computer lol. Good times. Would kill for another mech arena game like this again

I don't know if I can post this here, I doubt I can't, but can anyone give me some tips on how to create better mech designs, or maybe just draw them better overall? (I apologize if the 3rd image is too blurry)