I have been thinking about this for a while now. No one else seems to have written much about it that I can see. However, I consider it is an important aspect of working in all needlearts.
I suppose older, more experienced needle artists do not think too much about it, but the newbies and even intermediate stitchers need a bit of a primer on the back of their work.
Why is the back so important? The back is important because if it is too lumpy and messy, it will show through to the right side of the work as unsightly lumps and bumps, it will feel harsh to the hand and give the appearance of lack of knowledge or care in execution.
I guess in a way, taking care of the backside of your work is also part of the slow cloth concept.
People often comment to me on how tidy the back of my cross stitching is. This is because I use a loop start stitch so only the tails are threaded under stitches when finishing. My work lies flat. Also I do not cross over rows at the back, either, so nothing shows through the holes when viewed from the front. It has taken me an age to learn to do this, but it has made such a difference to my work.
If I made you a garment, say for example a jacket, but I did not finish the seams, did not line it or press it as I went along, it would not be very beautiful nor would it look good when worn. However, spending the time to finish the inside seams, press all the seams open or in one direction, lining and even handsewing where needed, although you cannot see these things from the outside, would make such a difference to the appearance of the garment and how it felt to wear.
If, like me in the needlearts, you are self taught, it is worth investing in a few "how-to" books and taking the time to learn to finish the backside of your work so that the front is beautiful.
Taking the time to learn how to finish stitches on the back so that the work is flat is necessary. Learn how to finish without knots; press your work from the back, using a towel when raised surface embellishments have been added. If necessary, prepare your fabric with the use of a tear or wash away backing, so that the front surface does not pucker. Spend the time on preparation to have a good backside and it will lift your front side to a much greater level. You will notice the difference yourself, and people who look at your work will notice the difference.
Time is of the essence ...