Hey ReyRey! You had something good going on! I just thought you needed a bit more room to expand! Also, don't be afraid to play around with big shapes in the foreground and background to really give the character a "setting"!
Technically, I thought the piece was good, but I felt the character needed more space between them and the table. Don't use objects to cover things up. Try drawing through, or visualizing through, the objects!
In this first version, I really tried to work with what you gave me as I know you spent some time on the face already:

However, I didn't know the story, exactly. I didn't know if your character was pointing to themselves.. so I gave them something that they were doing before being interrupted. When dealing with expressions, you sometimes have to tell a bit of a story? For example, a drawing of a man being angry isn't as appealing or entertaining as a drawing of the same angry man who is running after a dog that stole his underwear! (haha) So play with this! It'll make it a lot more fun, too! There are so many anime artists that just like to draw a pretty face, and I can see you already know how to do that, so take it to the next level and have more fun with it!
I also did another version which I find a bit more appealing, but it would entail you having to erase more of the original picture. I felt with the face tilted the other way, your character should be leaning on that arm. I just gave it a shot anyways..
But regardless, these are just suggestions and possibilities! Take whatever aspects you feel regards to you and try applying them in your own work! I hope this can be of some help!
Now Loki, yours was quite interesting, and I felt the part that you were getting "wrong" was actually, not the arm, but, in fact, moreso the shoulder. remember that if you're having a problem with something, go to the source. Go to where it connects and see how it's working.

You could also have a lot of fun playing with the position of the fingers and the angle of the hand to really drive home your picture! As you can see I tweaked just a few other things that popped out at me for you.
I got a little carried away in this other one (haha.. he's smoking two cigs) because I was kinda unsure of what he was holding.. and I wanted to try and use an element to frame the character. I noticed in your art you create quite simple backgrounds unless you're dealing with graphic elements. so I think you should try encorporating part of the character, or part of what the character is doing as part of the background to take it to the next level.
Overall it's great work and I'd like to see it when you've finished it up!
For both of you, I appreciate your patience and everything. I know I'm quite scribbly with the tablet when I sketch, but I guess that's just my way of figuring out things.
This is, by far, not a "final answer" as you can change up poses indefinitely.. and I'm also not perfect and striving to be better.. but I at least hope to have shone some new perspectives on the way you approach your drawings for next time!
Happy Arting! :3