I used 13 pages as a buffer... didn't last long
pro tip: buffer by time not page count, have enough pages for a certain time frame where you can replenish the buffer
like for example I have planned a 200 paged comic which will release 3 pages per week, that would take about 67 weeks to publish in its entirety and I can draw about 9 pages per 2 week, how big should the initial buffer be so that I can finish the comic with 0 hiatsu?
answer: about 31 pages in the initial release which gives me a 10 week buffer and would take me 7 weeks to replenish so I have a three week vacation before starting to draw again =')
of course this is crazy so I just choose to not do buffer and draw until it's finished and publish it weekly anyways XD