Couple of points. It's almost impossible to answer this question without more info. A slide? What kind of slide? Front or rear wheel? Sideways or forward slide?
I believe it is hard to say "if this, then turn into or out of the turn", as all crashes are dynamic and involve too many variables for a canned response.
Also, to say it's impossible to practice is not entirely correct. I think that it's possible to develop crash avoidance skills, but it comes with experience riding and balancing on your bike. The biggest way to improve balance is practicing slow speed drills. In my MTB courses I have students perform specific drills around cones, but the same can be accomplished by using your environment as obstacles. I tell my students that you won't always have cones to practice with, so find parking bollards, parking meters, trees, outdoor seating, etc.. to ride around in slow tight circles, switching directions frequently (figure 8's). The more you practice riding slow, the more you'll develop good balance on the bike. Pro tip for riding slow on an ebike (turn off the assist), use the rear brakes lightly and pedal (while applying light rear brakes). Super pro-tip for riding extremely slow, brake as above and concentrate on keeping the body/hands/shoulders relaxed. Similar to any active sport (like DH skiing), if you are tense, you tend to crash.
The other primary crash avoidance skill (as already noted) is awareness. Noticing a hazard in advance allows you time and ability to take evasive actions. So look up, look around, and look behind (often).