I think my husband is an excellent father-in-law. He NEVER criticizes them or anything he does to his wife (our daughter). He always tells his daughters that their husbands are their perfect fit for them !
He NEVER offers advice unless asked, and even when asked, he is very, very careful with his words.
He NEVER asks them about their finances
He often, praises their parental skills.
He loves them because his daughters do.