"Therefore by Him let us continually offer the sacrifice of praise to God, that is, the fruit of our lips, giving thanks to His name." (Hebrews 13:15)
Just as the priest offered sacrifices of burnt offerings and incense in the Old Testament, today, we offer sacrifices of praise to the Lord with the fruit of our lips, which are the words we speak in praise and thanksgiving to Him. The underlined expression, "giving thanks", is the Greek word, "Homologeo", which means to make confessions; making confessions to His Name.
Our sacrifices of praise are with words, and they go beyond statements like, "Lord, I give You praise." For it to be a true sacrifice of praise to God, it has to be mixed with substance from your spirit. You must have definite reasons for praising Him, and then voice those reasons. Your praise of Him must have content. Basically, you're supposed to consciously praise and thank Him in the Name of Jesus, for specific reasons.
The sacrifices of praise are confessions, declarations, psalms, hymns, and spiritual songs that you render to Him for His love, grace, and goodness towards you. They also refer to tributes or speeches that acknowledge and celebrate His majesty; confessions of His Word that we make to glorify Him. These confessions are the fruits and calves of our lips-- words from our mouths that give glory to God.
Therefore, when making confessions, say beautiful things about the Lord and give testimonies of His wondrous works. Proclaim what He has said about Himself and about you:
"...For He Himself has said... So we may boldly say..."
As you make those confessions in Jesus' Name, He (Jesus), as our Great High Priest, presents them before the Father, who receives your praise and worship as a sacrifice of a sweet-smelling aroma. Hallelujah!
Blessed Father, how great and glorious You are! You're the only true and wise God, who reigns and rules in the affairs of men. To you, Oh Lord, be all glory, honor, majesty, dominion, and praise! Thank You for making my life beautiful and filling me with Your glory, righteousness, and peace, in Jesus' Name. Amen.
Further Study: Hosea 14:2; Hebrews 13:15 AMPC