1. The purpose of a testimony is to glorify God.
Whether therefore ye eat, or drink, or whatsoever ye do, do all to the glory of God. (I Cor. 10:31)

2. In all testimonies, Christ should have the preeminence.
And he is the head of the body, the church: who is the beginning, the firstborn from the dead; that in all things he might have the preeminence. (Col. 1:18)

3. A testimony is for the purpose of thanking the Lord.
I will give thee thanks in the great congregation: I will praise thee among much people. (Ps. 35:18)

4. A testimony should praise God for His wonderful works.
Many, O LORD my God, are thy wonderful works which thou hast done, and thy thoughts which are to us-ward: they cannot be reckoned up in order unto thee: if I would declare and speak of them, they are more than can be numbered. (Ps. 40:5)

5. A testimony is not just speaking about the physical blessings from the Lord, but also what He has done for our soul.
Come and hear, all ye that fear God, and I will declare what he hath done for my soul. (Ps.66:16)

6. A testimony does not have to “wow” the human audience. It need not be some spectacular thing God has done. It can be something quite simple for which we are thanking the Lord.
I waited patiently for the LORD; and he inclined unto me, and heard my cry.’ (Ps.40:1)

7. A testimony should not turn into a brag-a-mony. Remember that we are praising God for His goodness, not highlighting our good deeds…
I am crucified with Christ: nevertheless I live; yet not I, but Christ liveth in me… (Gal.2:20a)

8. A testimony is not a public forum to thank or praise some other man.
I will give thee thanks in the great congregation: I will praise thee among much people. (Ps. 356:18)

9. A testimony should be to the point. Think and pray about what the Lord would have you to share ahead of time. Don’t ramble on and think of things to say as you are speaking.
He that hath knowledge spareth his words. (Prov. 17:27) The heart of the righteous studieth to answer… (Prov. 15:28)

10. A testimony is not just relating a funny incident. While it may include humor, the purpose of a testimony is not to make people laugh, but to point men to Christ and His goodness.
Let the words of my mouth, and the meditation of my heart, be acceptable in thy sight, O LORD, my strength, and my redeemer. (Ps.19:14)

11. We should approach a testimony in the spirit of respect and reverence.
God is greatly to be feared in the assembly of the saints, and to be had in reverence of all them that are about him. (Ps.89:7)

12. A testimony need not be presented in flowery language. It should be more like a child saying a simple, Thank you to his Father.
One thing I know, that, whereas I was blind, now I see. (John 9:25) Thank you Lord, for saving my soul!