I travel a tone so here are things I consider for my tank.
1. Water evap
2. Webcam of sump levels with painters tape indicating normal levels, im case ato malfunctions I can tell and take action.
3. Skimmer collection cup, sometimes I will hook up to a skimmate collection cup. I also have a webcam for this in case I need to turn off the skimmer or have it run only half days.
4. Fish feeder
5. Dosing automatically
6. Monitoring alk, esp in my sps tank. When you are not home, PH rises and growth increases so your dosing may not be sufficient while you are not home.
7. Saltwater additions via doser. Sometimes my skimmer takes a ton of skimmate out plus I have an alk tester taking out cample water so I have a doser dosing back saltwater into the tank to maintajn consistent salinity.
Might be missing something but this is it. Most important thing is to never mess with your tank right before leaving. If you know youre traveling, make this changes way in advance so yoi can work out the kinks because there are always kinks.