Warmup.
It might be one of the most important things you do all day.
I know it might seem pointless, or too easy, or too boring or whatever, but trust me, your body will thank you.
You are already committing to some time in the gym, what is ten more minutes?
If you are serious about getting better, faster, stronger more skilled etc, then you need to be serious about keeping your body healthy.
You need to be serious about warming up. And, while we’re at it, you should be serious about your post workout mobility as well.
A few minutes here and there will save you weeks and weeks of rehab. Where would you rather spend your time?