Constantly be on the look out for little ways to make your training more effective and productive without adding extra movement.
I'll give you an example.
I do almost all of my squats "starting from the bottom.
" Meaning that whether I'm doing a full range or a partial range, I'm going to set the rack at that height and start there instead of a traditional walk out and squat down style.
I think there are many advantages to doing it this way.
Not the least of which is safety, convenience, and real world applicability to the strength that you build.
If you've been doing all your squats starting from the top of the rack I recommend you give this a shot.
However recently I've been experimenting with doing an almost isometric hold while in the down phase of the lift.
Why? Because I can build a very controlled, lowering type of strength without adding any extra repetitions or exercises.
I can use it within the progressive distance system which I normally use.
So I simply squat the weight up and then on the way down, stop about an inch from the pin before I set the weight down and do a short hold there.
This way I'm continually building the strength to not only lift the weight, but control it more effectively and all I've added is few seconds to the repetition that I'm already doing.
Should I choose to come out and do a powerlifting competition and squat in it, I have less trouble transitioning from one style of squatting to the next and I've already built an applicable style of strength with very little more work and time.
There are multiple other ways you can look at training efficiency without adding extra time to your workouts.
Combining strength and cardio work, upper and lower body exercises alternated, using a "chain style" of lifting progression - a la Herman Goerner.
Explore, experiment and think for yourself.