Pursuant to our farbrengen on Shabbos I would like to share with you something I do for the sake of causing happiness and I believe it is Chassidus’s key advice on this subject, and I trust that it will benefit you as well.
Firstly Chassidus clearly defines (Tanya) that if we are not happy the Yetzer Hara will make us fall easily (primarily into depression,) hence it is necessary for us to take responsibility for us to become happy.
The meditation Ein Oid Milvadoi is the primary meditation that leads one into Happiness.
Quite simply, what I do is once in a while throughout the day I say, “Thank you for everything,” or “Thank you for continuous creation,” the idea of Yesh Me-ayin of course is that this very moment G-d recreated the entire universe, and hence that is something to be exceptionally grateful for and just by remembering and thanking G-d for this, (especially in speech,) we become happy.
Ironically, the entire psychological premise that issues in the past can be resolved is a misnomer for every moment we are faced with a constant unhappiness vs. happiness reality. I.e. if this very moment I will not actively see the good in my life or say thank you for everything, thus reminding myself of the good, there is no way I will be happy for the natural state of man is to see more of what he lacks than what he has.
So one hand it is all pretty simple – obviously including following Hashem through Torah and Mitzvos – yet on the other hand it takes constant effort.
The Rebbe gives the moshel (parable) to a car mechanic from the starter in a car. When you start the car there is a sudden boost of ability to move, so G-d gives us a kick start into spirituality by suddenly feeling aglow in his presence, however as soon as that glow wears off – and remember the starter in a car works barely for a few seconds – then it is up to you to push the pedal, not hard work, but if you let go you wont be moving, and then the Yetzer Hara will easily find ways to knock you over, get depressed, G-d forbid etc.