Subtitles From Txt Video Transcript - How To Effectively

I use SubtitleEdit to create subtitles, I consider as the best one.
There are various tutorials on the net. But it applies only to new subtitles. When I have transcribed text which I need to sync, edit it to save then in srt format, etc. Simply create captions in an efficient way. When I import them, it's about experimenting, if I'll have a lot of work to do with it, even though SE helps a lot in it itself. However, I want to ask if anyone knows tips on how to shorten this initial phase and make the most of automatic preparation.

Or maybe different sw to do same thing to suggest?
Thanks for any advice
Peter