Using "formal" density training as desribed by Ehtan Reeve you would start with double your goal - let's say 40 chins.
So you start doing 20 sets of 4=80
then, over time, you simply cut sets and add reps till you get to 1x40.
I would do 1 density cycle to 1x30, then wave back and go for 40.
I would also look at Pavel's russian ladders and GTG if you platau on density.
BTW if you ever do 1x30 be very, very happy and consider yourself a stud.