Have fabric, scissors, sewing machine....go.
Walking around a summer craft fair I saw numerous cross body bags and begin to check them out with interest. I wanted one.
I went home, dug out some coordinating fabric and started eyeballing a pattern. The biggest challenges:
1) Determining dimensions of the entire bag. I held up various other purses to my hips and tried to find a size that wasn't too big or small. "Does this size make my hips look too big?"
2) How long do I make the strap? "If it hangs here, does it make my hips look too big?" LOL.
3) Matching up the strap to the curves at to bottom. I should have marked the centers, but in the end I just cut the strap really long. didn't fuss with matching and just cut it off where I wanted it to stop.
4) Interfacing and strap innards. I wanted the body of the bag soft and not too stiff. I sorted through my stash of interfacing and came up with one that felt just right. For the strap I used a stiff webbed strap inside the fabric. It's not bunching up on my shoulder yet.