The lining is pretty decent it gives you a unique style
your coloring and shading also give this feel off
but I fell when you colour you forget to finalize
certain lines and shades... Not saying to stop colouring
just pay attention to the piece as a full before finalizing.
Well some tips would be not drwawing on your phone
but other than that start off by making light marks and the deeper the object gets as it goes.
The darker the shade needs to be also If you are going to shade you probably also need lighting, well atleast in the instance that you are drawing people.