Epicurean Humanism might be a novel mix, but it’s a mix of several quite old and well-tried philosophies.
It tries to combine all the good points of these movements. Some of the key principles are:
Happiness is mostly just the capacity for pleasure.
You can damage this capacity by helpless craving or by pointless cynicism.
Or you can nurture it by learning to take pleasure in small things, and giving up those habits of thought that get in its way.
The cause of unhappiness can be found in your thinking style.
The habits of thought that cause the problems are called absolute judgements.
By practice you can retrain these habits, to produce so-called relative judgements.
This does, to be sure, require some mental techniques (such as self-examination and mindfulness), as well as behavioural practice. But it’s by inhabiting the new character that you grow into it.
The habit of happiness is best learned among like-minded people
You can nurture these habits by meeting and socialising, mentoring, studying and practising and encouraging one another.
The details are too numerous and convoluted to lay out in full here. Which is rather the point of founding a body to promote the philosophy; it has to be shared in community, not taught in books.
And definitely not taught in blogs!