The kind of plans I should make

Should I work on a daily exercise plan or a weekly exercise plan?  I just realize that that is what I need to do.  I have lately been thrown off.  Maybe a daily plan would work considering I have actually done some exercise.  Should I also list on the benefits of any exercise I have done?  I didn't exercise today and now I have felt the effects of the lack of exercise like depression and tiredness. Exercise and diet matter and now I know that hindsight is 20/20.