It's best, as Christians, to declare many different things daily. Many times people declare healing over their body, a circumstance to change in their life, success in their life/finances (prosperity), etc. Declaring things daily, and calling those things that are not as though they were is a good way to exercise your faith. (Romans 4:17)
By declaring things daily, you're also forcing yourself within to adapt to those declarations. So, if we're to declare success, then eventually we should adapt to an attitude toward success so we can accept the success from GOD and be able to handle it.
What are some things to declare daily?
By declaring things according to GOD's Word, those things declared will be a reality in your life. Believe that!