I guess this sounds pretty lame but … always do all of your lessons. There are scripts out there that let you pick the lessons you want, and thus you can skip the vocab and just level up by learning the kanji. But in the long run it will probably hurt you because you don’t get enough exposure from only the kanji, and you don’t learn all the important readings.
I’m not saying don’t use the scripts, though! E.g. WaniKani Ultimate Reorder script. It’s great and gives you lots of freedom. Just make sure to use that freedom wisely.