DW and I have this scale for nieces, nephews, and other relatives that we are close to:
High School graduation - $250
College graduation - $500
First significant graduate degree - $500
Wedding - $1000 (the first one
There are also friends of our children, or children of our friends, that we have grown close to and in certain situations will also be placed on that scale, or sometimes more. For example, a young man who has been a close friend one one of our sons since kindergarten, has been through a lot but never complains, and was very supportive of our son when our son was going through a difficult time. This young man and his wife are so selfless that they are always wanting to do free stuff for us.