Everyone has their own way of gaining ideas when starting a project. There is no right or wrong way, find what works for you!
When I want to get some ideas going I usually start off with some sketches; little rough thumbnails to get the creativity flowing. Most of the time I get my best ideas when I just let go and don’t overthink too much.
Personally, I love working in Coffee Shops, as I find I can just zone out and get loads of ideas out! I’m still finding new ways to create ideas.