Right from the first year itself.
Why are you waiting for an ideal time to start preparation, when you can start right now.
If you have a clear mindset and you know that you are not going to go for higher education then preparation for placements should begin with the first year itself.
The problem is we think that we have a sufficient amount of time and we procrastinate to the point where we are left with no time. So it is better to start early then to regret la