Mariposa

well actually it is a pretty good butterfly and I love the word 'butterfly'<img src="e.deviantart.net/emoticons/let…" width="15" height="15" alt="" data-embed-type="emoticon" data-embed-id="394" title=" (Lick)"/>
but in this drawing you should put more shadings and brightness and especially the shadow
you need to make a gradient from the inside to the outside it will be more realistic this way, and of course the contour should be brighter as well, I mean a gradient brightness from inside to the outside I hope it makes sense ?(sorry if I can't explain better)
but overall you only need to play with brightness, shadows and especially gradients in this one
and also, since it is traditional try not to press on the paper with the pencil too much
good luck for the continuation and keep up the good work