Start with this Du'a
When you praise someone
قَالَ النَّبِيُّ صلى الله عليه وسلم: إِذَا كَانَ أَحَدُكُم مَادِحاً صَاحِبَهُ لاَ مَحَالَةَ فَلْيَقُلْ: أَحْسِبُ فُلاَناً وَاللَّهُ حَسِيبُهُ، وَلاَ أُزَكِّي عَلَى اللَّهِ أَحَداً، أَحْسِبُهُ – إِنْ كَانَ يَعْلَمُ ذَاكَ – كَذَا وَكَذَا
Qala-n-Nabiyyu salla-llahu 'alayhi wa sallam: Idha kana ahadukum madihan sahibahu la mahalah, falyaqul: Ahsibu fulanan wallahu hasibuh, wa la uzakki 'ala-llahi ahada, ahsibuhu, in kana ya'lamu dhak, kadha wa kadha
“The Prophet ﷺ said: If one of you must praise his companion, let him say: I consider so-and-so to be this, and Allah is the one who will take his account, and I do not declare anyone pure before Allah. I consider him to be such and such, if he truly knows that of him.”
Sahih Muslim 3000
Praise only what you actually know of a person, and leave their final worth to Allah (SWT).