I lost my Dad recently and I can tell you what helped and hindered.
I think grief is an entirely natural process that can't be rushed or medicated and while I can see how bereavement counselling could be useful if a loved one's death has caused the resurrection of other painful issues or there were unresolved issues in the relationship, I have a resistance to counselling being regarded as a panacea or 'go to' solution for something that is actually a normal part of life and needs to be gone through.
For me it helped enormously when people asked me if I'd like to talk about Dad and then listened if I did. I especially valued others' affectionate memories of him but had no need of people martyring him.
It really didn't help when people who'd lost their own parents assumed I felt the same as them and instead of listening to how I was feeling, talked endlessly about their own losses. I know for a fact that they meant no harm and probably thought this was 'empathy' or somesuch, but every bereavement is uniquely experienced and several times, I ended up re-sympathising with these people's losses and not talking about my own.
Some of the best people to talk to in fact were those who'd never experienced bereavement. They didn't try to empathise and just listened to what I was saying, stayed on topic, asked questions and paraphrased. DH and the kids were just brilliant, even though they felt the loss too.
I suppose the other thing I'd say as an observer and may or may not be relevant to you OP is that the best helpers are those who've got no agenda. I've seen a few unsavoury incidents where a widowed man or woman suddenly has an army of opposite sex helpers who, under the guise of being ministering angels, are actually hoping to form a sexual relationship with the widowed person. That leaves a bad taste in the mouth and is fairly transparent to people looking on.