RE: Ghost ship skull 1/2 sleeve
Unfortunately I really think you have missed the mark with this one. You havn't told us your experience level so I cannot take that into account, but here are a few things for you to consider.
Did you look at reference material of your subject matter to base your ship drawing on?
Firstly the way it justs cuts off at the top of the arm was a bad design choice. What purpose did you mean this to serve? The masts of the ship are the same thin width the entire length, they should taper from thick at the base to thin at the top. The ropes have alot of inaccuracies that don't make sense.
The sun is an unnecessary element it isnt serving a purpose and just looks out of place.
The colours in your sky are very poorly saturated, as is the yellow tones through the skull. Reassess your application technique of colour packing. What needles did you use, were they good choices?
The composition just isn't working well.
A lot of space through the middle of the design is wasted space & background and fill in which is taking up room which could have been utilised better by drawing the ship as the main element, also by making the ship larger you could have better achieved all those great details a ship should have. Did you experiment with different ideas, placement of objects, why did you pick this composition for your drawing?
The illusion of above/below water just hasn't been pulled off in this piece. Just colouring the water a different colour is not enough. The wave on the left of ship is dragging viewers eye down to skull, the viewers attention is not drawn through the design or even towards the shop, to put it plainly the flow is all wrong.
Your directly elements have been used to create the opposite effect then desired. Very horizontal and vertical,remember those s curves.
I will leave it their as I do not want to pick your piece apart too much as I am unaware of your experience level.
Consider what I have noticed and think about what you could have done differently. Perhaps do a sketch of how you could improve design composition, flow and detail of this design, post a pic for us to see if you understand your mistakes