I have read stories here of people quitting drinking and smoking at the same time. I guess it might work for some, but I can only imagine how hard it must be.
When I was in detox for 6 days, I met each morning with a psychiatrist, and he told me that his recommendation was to work on one addiction at a time. After I had at least six months of sobriety, then I could consider quitting smoking.
I think that is good advice, but, I feel like these things are different for different people. While we all share the same affliction, we are individuals and must figure out what works for us.