I like to play a 5 note scale starting with the open G first, up the the 4th finger then back down again. I try to play it as fast as I can, in tune, and on all 4 strings. I’ve been doing it for years, but recently saw a vid that called this an exercise (forgot the name, however). It helps build up finger strength and dexterity. Do you have a fav exercise?
Take a simple song like Twinkle Little Star and try to play it and fifth position (or any for that matter) and play it until I’m confident where the notes are. Etudes don’t hold my attention well but if I’m playing a song I already know and know how it should sound, I feel like I learn better. Been doing this for a month and I’ve already gotten much more comfortable in the higher positions.