I do it as early as I can and it makes me feel like a responsible adult, especially because I'm using one of the swaggier filing solutions instead of turbotax or whatever so it's nice and free
This time around it's a little more annoying because I have to deal with self-employment stuff from my gig economy job last year. But I actually might get a slight refund which I wasn't expecting so 
I used the IRS's digital version of the 1040 form last year. It fills some of the fields automatically so you don't have to risk incorrect additions or small typos.