/ic/ - Artwork/Critique

Please critique! I just started using Procreate on the iPad and am having a lot of trouble blending. For the boots, I completely forgot to use a soft brush for blending but I actually prefer the way they came out compared to the rendering on the t-shirt.
Also I took a lot of time with the proportions of it all and still somehow got the front boot looking strange.
Questions:
How do artists use soft brush for blending while still achieving a professional looking result? More often than not I felt the rendering on the t shirts came out muddy and amateurish.
What is the best way to blend? I used the eye dropper tool and haphazardly drew back and forth with lowered opacity until it looked OK. This was difficult as the pen pressure controls the opacity on the brushes.
What should the background and foreground be for this? I drew this on a shitty ikea bedside table.
Final Question: what is the process for drawing fabric? I blocked in approximate locations of shadows but they ALL ended up being wrong. At the end I just kind of winged it. Is it actually possible to draw fabric 1:1 without making approximations?