Even when it's a longer trip, I wait to file right before I head to the airport. Although I probably don't have much say, I like to think I have some control over what routing and altitude I am going to get. Waiting until the last hour gives me the best wind and weather forecasts and heavily reduce the amount of wasted time day/s before trying to figure out my route.
Ideally, I have a passenger and can do it all driving to the airport.
Or even better, if I am flying within the NorCal Tracon environment I just review weather, notams, tfrs etc. on my iPad and ask for a TEC clearance if I need it. That only takes about 5 minutes of my life to do