For a general future time:
* Afterwards
* Subsequently
* Eventually
* In due course
* At a later date
* Soon
* Shortly
* Presently
* By and by
For a specific future time:
* Tomorrow
* Next week
* This evening
* In the future
* Down the road
* At some point
* When the time comes
For a more formal or professional context:
* Henceforth
* Hereafter
* At a future time
* In the coming days/weeks/months
* Upon completion
To express a delay:
* Hold on
* Hang tight
* Just a minute
* In a bit
* In a while
To express a change in plan:
* Instead
* Otherwise
* Alternatively
* Rather
To add emphasis:
* Immediately
* Right away
* Without delay
Informal alternatives:
* After a bit
* Soonish
* Whenever
* Whenever you're ready
It's important to choose the word that best suits the specific situation and desired tone.