Along_the_Wire Playing live and recording mixes, are, believe it or not, wildly different imo. For the most part, you have to master one before you master the other, not many people get gigs without being able to put a recorded mix together. Putting together mixes for repeated listens if then different again. They all take different approaches. All you can do is keep practicing, keep listening back, and get to know your records as much as you can.
On that last bit, maybe only go record shopping every three months or so. Back when I learnt on vinyl, a good choon would have a shelf life of up to a year, possibly more. So that gave you a year to work out what other tracks it worked well with, and those other tracks you might have had for a year too. So you would know those tracks inside out. The worst part of digital is having too many tracks and not knowing them. So, three months of working out a 90 - 120 min set should see you get familiar with it all.
