You've probably heard about Malcolm Gladwell's conjecture (in his book 'Outliers') that you need to put in at least 10,000 hours of practice to get really good at something. There's some debate about it, and Gladwell has said that it's no guarantee and depends on the activity. I don't think many of would argue though about the benefits of practicing something regularly, especially if you practice in a way that extends your skills rather than repeating what you can already do comfortably (i.e. intentional or deliberate practice).
So why do we wait for an 'opportunity' to photograph. A vacation, a different city, a sunset, a model, a skyline. I often have to remind myself that the interesting moments, stories, aren't just out on the streets. They can be indoors, in the family, the details, the relationships, the interactions.
Street photography is often about finding the extraordinary in the ordinary, turning something mundane into something beautiful or fascinating. Showing details that might otherwise go unnoticed. Where better to practice those skills - of seeing, of searching, of noticing light, of creating compositions - than at home.
Patrick La Roque is a great example of this. His blog is regularly illustrated with creative shots he's taken around his house, finding details and using light to create interest.
Even if you're not aiming for that 10,000 hours or 10,000 images, there's no need to wait for better weather, or the next trip or (telling myself this) a new camera.