As a player who currently can cast Guidance, I find its decision making process a little less than exciting. Essentially, if I'm not concentrating on a spell and there's no time pressure, cast Guidance. I'd like to make the spell more meaningful. So my thought:

Guidance

Casting time: 1 action
Range: Touch
Components: V, S
Duration: Concentration, up to 1 minute
Classes: Cleric, Druid
You touch one willing creature. Once before the spell ends, the target can roll one ability check with advantage. The spell then ends. The target cannot benefit from the effects of Guidance until they have completed a short rest.

I think this provides a more meaningful decision point behind the spell, since it can't be used for every check. It could even provide a meaningful benefit in combat, if you were to use it on, say, your barbarian friend who was planning on grappling someone. I do worry if it is almost too weak, since Working Together wouldn't stack with it. Would allowing it to be used for attack rolls or saving throws then make it too strong? (Per my understanding, those don't qualify as ability checks).

PS: I apologize if this is formatted strangely, I'm still trying to figure out how to make things look nice on Stack Exchange.