Setting some to do's is a great way to keep you on schedule and help you plan out each day. They help you remember what you need to do and when. We use them constantly at work, as it helps keep us reminded of what we need to do on each file and then we have a page that lists all of them in one spot.
The problem I have run into in the past is setting too many to do's. If you set too many, you will not be able to get them all done when they are due. Just the simple act of setting them can eat up much of your time as well. Thing about it. If typing out the details of the to do take on average 2 minutes for each one and you do 30 per day, that is an hour right there just typing to do's.
Only a certain number of them should be set for each day. You should always set one for the things that can get you in biggest amount of trouble. At work, for me, that would be paying benefits when they are due on my lost time claims. At home it may be paying bills or tests that are due. After that, I recommend setting to do's that affect other people. At work that might be a meeting or group project due date, at home it might be a birthday party or some other social gathering.
There are also those to do's that should never be set in the first place, because all they do is create clutter in your life or amongst your more important to do's. An example at my job would be not setting to do's for medical reports that will automatically come in and get attached to my file anyway. At home, it might be bills you have on auto pay or grocery shopping, etc. You are going to do those things as they come up anyway, so why set a reminder.
Lastly, if you set a to do and find yourself continuously moving the date back, just delete the thing. If it can be pushed back week after week, you probably don't need it anyway. Only set to do's / reminders for the absolute most important things. If you don't, you will find your list cluttered and have a feeling of being overwhelmed. I suggest treating each day as though you only have half of that day to do what you need to do. It will help you focus on the more important things that you need to set reminders for.
Are you a list person? What do you use to keep track of your to do's? Do you ever find yourself having so many that you never get them all completed?