I've done state taxes by hand in 5 different states, including nonresident taxes. All of them go through the same basic process: copy your AGI from the federal

I've done state taxes by hand in 5 different states, including nonresident taxes. All of them go through the same basic process: copy your AGI from the federal form, adjust for local purposes (which for me meant running my finger down the list of adjustments in the instructions and going "nothing applies"), compute taxes, add in the use tax, and you're down. If you've got multistate tax issues (whether nonresidency or part-year), things get spicy because you have to allocate income across the different states. And even then, the only difficulty I had was doing CA nonresident taxes, because it turns out that there's a weird collision with CA and a few other states for nonresident taxes, the other one being the state I lived in at the time. And CA's instructions doesn't tell you about needing the other form unless you read the instructions for that form in particular.