On the first start let it completely warm up idling usually 15 minutes or so, then after that accelerate to full throttle maximum speed possible and then back off to normal riding speeds. Ride around for a bit then hit full throttle again. Usually normal city riding simulates this close enough. Do this continuously for the 25 miles, try to do it all in one run, and then change the oil. This is considered the hard break in process. It helps seat the rings and cylinder with maximum pressure. It's seems counter intuitive but if you read this site it makes sense.
http://www.mototuneusa.com/break_in_secrets.htm
I've broken in my engines like this. And throughout owning numerous GY6 scooters I've never had one that lost compression or consumed oil due to ring blow by also testing oils I've found it to have less gasoline contamination upon oil change than the used scooters that I bought. This tells me the hard break in did serve to better seal the cylinder.
As for oil change. I'm also a member of the bobistheoilguy forum and I take my oil seriously. I've determined through my engineering knowledge the pattern for particle build up in oil changes during break in is roughly logarithmic in nature. So I determined the oil change interval should be roughly exponential to keep particle content in the oil at a constant minimum while not changing oil more often than necessary.
This means changing oil at 25 miles, 50, 100, 250, 500, 1000, and then after that the engine is fully broken in and switch to synthetic and change every 1000 miles after.