One thing that I do is learn the available kanji before I add them. If I have 24 available kanji, I’ll learn 12 on the first day, then the remaining 12 in the next day. Then on the third day I test myself, and if I get most of them right, I add them then. Otherwise I would die.
What do you mean by add them? 
Add them as in doing them in the lessons, adding them to your reviews
I do radicals and kanji first, and so far I haven’t had a problem with vocab piling up. I also do my lessons in 10 item batches because it makes me take a lot of time while learning them because the review at the end will be 10 items instead of 5.