Over 50 years ago as a kid I started playing Atkins and Travis styles, fingers and thumb only because I heard them on the radio and developed that style, and didn't know guitar picks existed.... Later I started using thumb picks, then flatpicks. I developed a simple technique to move the flat pick between 1st and 2nd and hold it there till I needed it again. It takes practice but works for me, but occasionally I will drop a pick, so I always keep one handy. I still do that, but I have well developed callouses on thumb and 3 fingers. My style may be crazy, but works for country double stops, jass, and a little classical too.