You do it in public.

Recommend orgasm and then drawing what you fantasized about.

I remember reading a hentai about this. The artist was forced into tucking his dick in such a way that it looked like a vagina, and also crossdress. He managed to draw his doujins without climaxing and only got to get laid when his first tankoubon (sp?) got greenlit.
 
Edit: Daiwari To Josou To Assistant by Ikuya Daikokudou.
 
Or you can check Slut Inspires by s-nina if you are into that sort of thing.
 
Basically, deny yourself until you are done drawing.

Well, you can try to draw with one hand…

it’s okay to want to masturbate and not do it. that makes it feel better when you do. it’s just edging, and a lot of artists drawing lewd get really, really good at it.
 
it’s also okay to masturbate while drawing lewd. once you orgasm you can start “edging” again, giving you time to draw, and with practice you’ll be able to stretch it out longer.
 
of course the ultimate solution is to have someone getting you lewd for you, while you focus on your art. this causes super high quality arting.

You say that like it’s a bad thing to enjoy what you’re doing.

hmm.. have you tried being tortured by you life with humanity and the focusing it into hatred?

Draws without looking at the drawing

See a mental health expert? shrug Better safe than sorry.

Develop a fetish for orgasm denial.

Replace your chair with a Sybian and just keep it on while you draw.

I don’t find my own drawings attractive so it isn’t a problem for me.

wank first

Take breaks often for irl lewdness while drawing.