I used my not-so-technical system of clothespins to get it in the right place before applying glue.
I applied wood glue and cinched it down with twine.
Afterwards, I tightened up iffy spots with some Zap-a-gap CA glue with a squirt of setting accelerator.
Later, I did the same process for the front gable roofing.
Then, the porch roof and the porch railing on the sides went up. It's looking pretty good!