However, coming up with ideas is far, far easier than executing on them. If you're in a situation where you can't generate ideas, I would recommend reading/watching various advice on the subject in the YC library and elsewhere, to try and get closer to the right mindset to be open to opportunities. Then pay attention to all the little things you ignore day to day. Every time you find yourself getting frustrated with a company or process, that could be an opportunity in disguise. It's also beneficial to broaden your work experience. Go work in a different field or a field at an intersection with yours and pay attention.
Be Mindful of The Living Force as you go through life :)