Help Me, Help You
The first thing to consider is that we ultimately wan to help our students gain skills they can use in life, not just ones they need right now to turn in an assignment or sit in their chair. When we help them learn how they function best, and ways they can improve their own lives, they realize how much control they actually do have in their environment and their own success. When they know you are just trying to help them and not control them, then they will start to listen to your suggestions.
Busy Minds
The second thing to consider is how much is going on in the mind of a student (or adult) with ADHD. We often see surface level behaviors that look like kids are being lazy, defiant, or just not caring, but the reality is much different. We cannot assume that our interests and priorities are theirs. We need to dig deeper and find out the root cause of why things may not be getting done or why there may be off-task behaviors.
Practice, Not Preach
The third thing to consider is that we need to help kids practice how to self-regulate and control their focus. This can be done with games but also can be done by having them listen to podcasts with tips. Kids need help to form new habits such as writing out to do lists, keeping an agenda, and chunking apart larger projects into smaller tasks.