If you have people in your group who are not used to giving their character backgrounds this could well take a lot longer. We had to pretty much coach everyone through each step. For instance, coming up with the stories was easy for me, but picking aspects and abilities was not. However for another guy in the group the technical stuff was easy and stories were really hard.
Keep in mind that via the on-the-fly stuff (YS p. 69, har har), you have the option of entering play without a background and developing your aspects and other abilities as you go. If that's your hurdle, don't sweat it. Leave whatever you need to blank.
Advice-wise, I tend to find (though I'm not assuming this is your group) that people's biggest obstacles to good aspects and background stuff is overthinking it. Simple but evocative works best. There are only so many plots in the world, right? Don't worry too much about cliche. A wise video game once said to me, "Nothing is a cliche when it's happening to you." It's your roleplay that's going to bring the character to life and set them apart anyway.
For aspects, the thing to look for is, "What is the most significant thing the events of this phase tell me about who this character is?" And then, "Is that a double-edged sword? How?"
And if you find out that doesn't work, you get a chance to review and make changes at the end of every session anyway, via minor milestones.