So as an example of a song I'm trying to learn. Still got the blues for you by Gary Moore. Chords played as arpeggeos with all notes ringing out. On one hand I'm trying to fix some problems with transitions that aren't perfect..... and at the same time if I think about that change before hand I'm actually just screwing up even more. How do I give it my attention, without the stress of anticipation ???
When a chord has to be played, strummed or arpeggiated, it's best getting all the appropriate fingers down onto the strings in one go.
Hammering on each chord during practice time is a good ploy. Eventually, all fingers will land together, and feel solid. A few minutes a day for a couple of weeks will often suffice. Try one chord followed by the next, just two at a time to start with. It'll also mean your changes will be tidier, without the need to put in an open strum as you change - something a lot of self-taught guitarists manage to 'learn'.
A bonus with such a song is that those changes occur in many other songs, in different keys, so actually, you're sort of learning other new stuff unknowingly!
Were 'on one hand' and 'before hand' chosen specially?