Not knowing birth time interpretation

When making a chart for someone whose birthtime you don't know, would you suggest making it noon and then just looking at the outer planets in signs and aspects?

Ideally, I would get their birth time, officially. A time that is likely accurate to within a few minutes is second best. Next best would be to rectify the chart.

If not, I would look at the planets in signs and aspects, but definitely focus more on the personal planets and aspects to them (whether from outers or others).

I don't know anything about rectifying but will look it up.
Thx.
I cannot get the actual birth time, or general for that matter.