The intentions behind what you do is what will manifest. When explaining to people wanting to embark on smudging, I reference a pastor/preacher coming to the home, opening all windows and doors, using things such as sheets, oils, and water to "dress/bless" the space, and praying and quoting scriptures to cleanse the surroundings.
This is no different when it comes to smudging. In fact, Psalms 91 is an excellent reference for a prayer of protection. Just as is said in church, "when you pray, make your words specific". This same mentality applies, the only thing to remember if new to smudging is to be sure you are specific in what you are proclaiming, and that it be done with good intention!
You can also call aloud affirmation sentences such as:
"I speak and abundance of clean energy my way!"
"There will be peace within my home coming and leaving!"
"Dark and negative energy has no place being here!"
"I manifest joy peace, love and a sound mind!"
"I am making room to more in my life!"