50% of your issues can be eliminated during the drawing and design phase. use reference to draw those things you aren't intimately familiar with. use GOOD reference and make sure its all consistent with everything else. poorly put together patch work looks like dog s&!t, so if you must...make sure it looks seamless, which brings me to...HAVE A COMPLETE PLAN before you start tattooing. not only are these gaps and mysterious floating banners embarrassing for your client but they seriously handicap what you can do later since you've painted yourself into a corner. get all of this worked out in your sketches, revisions and drawings BEFORE your client sits in the chair.
most of your technical issues can be addressed by just SLOWING DOWN. your shading in particular i think you only go by the sound of your machine, everything is done in a 'bizz, bizz, brrrrrrrrrrr' cadence and obviously it isn't working. your line work is all over the place. you said you tried to sculpt them out but none of the evidently sculpted lines make any aesthetic sense.
draw. draw your ass off. when you're at the shop and you're not drawing or tattooing you should feel like s&!t because you're not being productive. keep it small, simple and perfect and build on that. your detailed, convoluted, haphazard 'just for fun' drawings are only reinforcing those bad habits we're trying to eliminate, especially when you aren't even trying to apply these new fundamentals to them