Quick and easily printable handle for the cheap pickset you can buy from for example banggood (SKU113026).
It's a frictionfit and I have not needed any glue but you could give it a drop if it starts feeling loose.

The handle will hold picks that are 8mm wide and 0,5mm thick the slot depth is 38mm (the pick will protrude 2mm when inserted as illustrated). The printed handle is 8cm long, 4mm thick and 12mm wide.