LPT: When offering condolences to someone who is grieving, focus on THEM, and avoid speaking at length about the person they lost.
This mostly extends to the initial reaction and condolences when someone tells you someone near or dear to them has passed.
It can be hard for the grieving party to have the concerned party extoll the virtues and the many wonderful qualities of the deceased. It serves as a continual reminder for what that person has lost and can reopen the pain of loss. The grieving party almost certainly knows you liked and respected the deceased (and definitely doesn't want to know if you didn't).
For example, if you were to tell someone "My husband Bob passed," and someone responded, "I'm so sorry, he was the one of the best people I ever knew," that brings the grieving party back to the gravity of what they've lost; it reminds them, again, that something deeply precious to them has been taken from their lives forever, and that can bring about pain and hurt.
Instead, focus on the grieving person - ask them how they are, ask them what their plans are, and remind them about all the good things in the world and in their life to help make it easier for them.