[meekrohprocess]

Don't leave without a concrete goal and a timeline. What do you want to work on, with who, and why? Don't give up the pay and benefits until you can answer that, and make sure that you budget for N months/years out of work. Idealism doesn't always pay well.

IMHO, don't sweat the IP stuff to much, until you start spending a lot of off-hours time on a serious project (website, incorporation, etc). If you don't have a specific business plan, don't sweat it.

That might be an unpopular opinion, because it probably would leave you vulnerable in most at-will employment contracts, but as long as you don't take anything with you when you leave, big companies are unlikely to aggressively enforce anything.

And this should go without saying, but leave on good terms. Do right by the people who you work with and don't leave them holding any bags. It's the right thing to do, and you might want their recommendations if things go belly-up. Plus, part of the reason why the company is unlikely to go after you on technicalities is that they want to hire creative people like you in the future.