Between a few particular sections in Tzaavas HaRivash and Keser Shem Tov, we can learn a wonderful path in avodas Hashem. Of course both of those seforim and the entirety of our mesorah contains advice in these areas, but specifically in regards to avodas Hashem b’derech haChassidus, these are wonderful.
The Baal Shem Tov teaches us that the Yetzer HaRa has various tactics to distract us from serving Hashem. Sometimes it tries to convince us to take on extra chumros (stringencies), and others it fills us with obsession to be over-the-top careful about mitzvos; and yet other times the Yetzer HaRa fills with sadness and regret by convincing us that something we did was an aveirah when there really was no sin whatsoever, and even if there was some amount of sin Hashem will forgive us once we return to Him anyway. The most important thing is to afford sadness like the plague, even to avoid crying for any reason other than great simcha or feelings of d’veikus (cleaving) with Hashem.
The ikar is to spend our time rejoicing with Hashem, to be happy when learning Torah and davening, indeed in all things we do with that recognition that Hashem is ממלא כל עלמין (filling all the worlds). Even in times when we can’t learn Torah or do explicit mitzvos, the strategy to avoiding sadness and turning whatever we’re doing into avodah is to recognize that Hashem wants us to serve Him in this particular way at that time. The way to do this practically speaking is to know that Hashem fills all the worlds, and that whatever happens and whatever situation we are in is the place that Hashem wants us at that time in order to elevate the sparks of holiness contained within that place and time.
As we head into Yom Kippur and evaluate our conduct over the past year, we must figure out what we should do in order to grow spiritually. Whether that’s taking extra time for hisbodedus or hisbonenus (contemplative meditation), or taking on learning a daf Zohar every day, the important thing is that it should be focused on positive growth, rather than focusing on restriction. While restriction from negative behavior is important, according to the path explained by the Baal Shem it is more crucial to increase positive behavior in order to bring more Ohr (Light) from Hashem into our souls and lives. From working on positive improvements we can advance much further than working on restrictive behaviors, and better avoid the tricks of the Yetzer HaRa.