Of course it depends on the age and independence of the kids. My bias is towards minimizing the amount of crap on the kids bikes. Every attachment is a distraction. And the kids don't really need instant continuous access to drinks and snacks, unless those are things they expect at home. Let them focus on riding safely. It was easier for me to throw all of their stuff into a bag and strap it to the rack on my bike, or put it in a backpack. Likewise when we were just getting them into hiking, camping, etc.
At a younger age, we walked our bikes across busy streets. I also taught them that they have to make their own independent judgment about whether it's safe to cross: "Just because I crossed doesn't mean it's safe. You have to be watching out for yourself." On streets, I let them go in front of me, so I could watch them, and to put myself between them and any car approaching from behind. This also gave them a sense of responsibility and control. Naturally they get more liberty as they demonstrate that they can handle it. Being allowed to go out on their bikes after dark didn't start right away.
Find excuses to go on short rides in town: To the library, ice cream shop, park, school, etc.
Let them participate in maintenance! Both of my kids have rebuilt bikes from a pile of parts. A work colleague of mine gave me her "campus bike" and my daughter got it working and took it to college. A relative of mine had a great idea that I think is cool: He got both of his kids a basic took kit for Xmas, and then every year they get a couple more tools. You could do that with bike tools as well.
Have fun!