I am a modler from a much earlier period of time but I did a lot of woodworking over the years and my grandfather was a tool and die maker. both taught me about sanding and smoothing. Gramps of course worked with mills and lathes and metal billets for the tools. When he got it all finished and before he took the part out of the machine he had a pair of very soft leather gloves he would put his hands in and rub over the entire piece to feel it. If there was a rough spot or burr left the gloves protected his hands but they caught on the bad area and he would keep working until it was perfect in his touch.
And wood working it is a lot like that too. You do your sanding and smoothing and then you rub your hands over the work and you will feel what you can not see and know that you still have work to do. I recommend this for your modeling also. When you get your sanding done and parrts washed for paint put your glove on and rub over the model and see if you feel any dips or imperfections and take care of them now instead of later when you have painted the parts.
And wood working it is a lot like that too. You do your sanding and smoothing and then you rub your hands over the work and you will feel what you can not see and know that you still have work to do. I recommend this for your modeling also. When you get your sanding done and parrts washed for paint put your glove on and rub over the model and see if you feel any dips or imperfections and take care of them now instead of later when you have painted the parts.