What’s a sensible way to approach a planetary invocation?

There isn’t one standard sequence across all traditions. If you’re following a particular system, use its instructions rather than combining names and steps from different sources. A simple structure is to settle on a clear purpose, prepare a quiet space, say the prayer or invocation used by that system, make your request plainly, then close with thanks. A planetary hour is part of some approaches, but it isn’t a universal requirement.

Angel contact and zodiac timing are also tradition-specific. If the source you’re using connects a planet with an angel or a sign, follow that framework; otherwise, you don’t need to add those elements just to make the ritual complete.

I’d separate the devotional question from the practical one. You can treat an invocation as prayer or focused reflection without assuming that a being will answer. If you do interpret an experience as communication, keep room for uncertainty and don’t make major decisions based only on a perceived message.