Every time I shoot if I have access to a good 100 yd point of reference. A few minutes and a quick 3-5 round group to confirm the zero just confirms everything is still good and can save some frustration before you start slinging rounds at extended ranges. Its one less thing you have to diagnose if you start having issues.
Honestly, shooting groups at 100 yds is also a good practice just to reinforce good fundamentals and practice the basics. Its also a challenge to see how tight you can get the groups and puts you in a good mindset before you start pushing out to further ranges.
If you shoot with a couple of buddies, another great drill to shoot at 100 yds with precision rifles is what we called "know your limits". Place different sizes of shapes (square or circles) that start large and keep getting smaller and smaller. Take turns shooting each shape starting from the largest down to the smallest in sequential order. When you miss, you're out. Whoever takes out the smallest target wins. It is fun, get's you and you're equipment warmed up, and confirms your zero.