Question avbout going places with a progression

I have a song that goes C#m, E, B, A for the man progression. I am looking for a chord progression to follow it for many the chorus or a bridge. I am not sure how this stuff works though. I know it is a 1,3,7,6, progression in C# natural minor but how do you know what chords you can plop in the change things up? I see songs that use chords that aren't contained in the scales or just don't sound right to me but sound great in the song.

I don't know where could I go from the A basically?

are you trying to change keys or something? because honestly I would say just find something that sounds good to YOU first because you'd be surprised at how some chord progression, albeit 'correct', may not be as appealing to the ear.

This probably isn't very helpful, but hopefully one of the other members could help more than me.

there are chord substitution rules . I have no knowledge of these however, so i'll agree with Case, use your ears!

Sometimes you can transition to chords from other keys. Let's take your progression for example.

You go, C#, E, B, A. Let's look at the last two chords (I would label them V and IV... just cause I have a habit of labeling everything in the Ionian Mode). Since you are going to the A, and coming from B, you could interject something to maybe make your way to the A. What we can do is look in the A major scale. The sub-dominant of A major is D (A, B, C#, D, E, F#, G#). So, since we know that the IV in A major is D major, we can use that chord to transition to it, now making A major your new home. Then you could continue with an A major progression, or go back to the C# minor progression

i would modulate 2 a different key,lets see yer in the key of c#m,so u can modulate up a 5th 2 g#m,or u can modulate down 4th 2 f#m,or u can even do something like this,when u modulate 2 g#m u can even modulate up a 5th from g#m 2 d#m which is the secondary dominate,you just have 2 make sure u return 2 the original key in this case c#m before yer song is over,,,hope this is some what helpful 2 ya,,,oh just in case ya don,t know what modulate means it means change keys,,,